Objective To evaluate the effects of the non-supine position and the supine position during the second stage of labor on delivery outcomes.Methods In total,642 singleton term primiparas in the Fourth Hospital of Hebei Medical University between January 2013 and March 2014 were divided into the non-supine position group (n=320),which included the lateral (n=204) and hands-and-knees position (n=116),and the supine position group (n=322) according to primipara's choice.Delivery outcomes in the two groups were compared using the Student's t test,Mann-Whitney rank sum test and the x2 test.Results The incidence of caesarean section was similar in the non-supine position and supine position groups [0.9％(3/320) vs 1.9％ (6/322),x2=0.438,P=0.508].Compared with the supine position group,women in the non-supine position group had a higher incidence of perineal lacerations grede Ⅰ [85.2％ (270/317) vs 65.2％ (206/316),x2=33.884],longer duration of the second stage of labor [48.0 min (31.0-78.0 min) vs 41.0 min (25.0 67.3 min),Z=-3.066] and greater blood loss after 2 hours of labor [240.0 ml (200.0-287.5 ml) vs 210.0 ml (160.0-260.0 ml),Z=-3.736],but a significant reduction in posterolateral episiotomies [5.3％(17/317) vs 23.4％ (74/316),x2=41.908],perinealedema [13.6％ (43/317) vs 21.2％ (67/316),x2=6.430] and meconiumstained liquor [20.8％ (66/317) vs 33.2％ (105/316),x2=12.356] (all P＜0.05).In the non supine position group,fetal heart rate showed fewer early decelerations,variable decelerations and late decelerations than in the supine position group [10.1％ (32/317) vs 17.1％ (54/316),x2=6.593; 2.8％ (9/317) vs 6.6％ (21/316),x2=5.079; 3.2％ (10/317) vs 7.6％ (24/316),x2 6.139; all P＜0.05,respectively].Conclusions The non supine position during the second stage of labor may improve delivery outcomes.

Objective:To explore the teaching effect of case-based learning (CBL) in patient safety course.Methods:A self-made CBL teaching effect questionnaire was used to conduct an online survey on 212 clinical medical undergraduates from a medical college in Chongqing.Results:A total of 212 questionnaires were collected, with 100% of effective recovery rate. Among the students, 91.0% believed that CBL teaching quality was high; 92.4% were satisfied with CBL teaching; 62.7% were the first to experience CBL teaching; 96.7% preferred CBL teaching; 94.3% said that in the future teaching, they would like to accept CBL Teaching. Most students thought that CBL played a vital role in stimulating learning interest, improving learning enthusiasm, activating classroom atmosphere, broadening learning ideas, exercising independent thinking ability, and facilitating the ability of theory connected with practice. Suggestions for the CBL teaching of patient safety courses are summarized into the following three keywords: multiple cases, more interactions, and more similar teaching.Conclusion:The application of CBL in the patient safety course is worth promoting, which is conducive to improving the teaching quality.

Objective:To investigate the value of MR subtraction images in improving the interobserver agreement for Bosniak Ⅱ, ⅡF, and Ⅲ cystic renal masses (CRMs) with Bosniak classification version 2019.Methods:From January 2009 to August 2020, 323 patients (335 CRMs) with surgical pathology results and complete preoperative MRI examination (T 2WI, T 1WI precontrast images and enhanced MRI in corticomedullary, nephrographic, and excretory phases) were retrospectively collected in the First Medical Center of PLA General Hospital. The CRMs of Bosniak Ⅱ, ⅡF, and Ⅲ were selected and classified by 2 experienced genitourinary radiologists according to the Bosniak classification version 2019. The "Subtraction" function in the American GE ADW 4.4 workstation was used to perform subtraction images reconstruction on the enhanced images in the corticomedullary, nephrographic, and excretory phases. Blinded to pathologic information, the other 2 radiologists independently classified the enrolled CRM cases with and without subtraction MR images, respectively, with an interval of 1 month. Ultimately, by using weighted Kappa value, interobserver agreement was evaluated, and the differences in weighted Kappa value were compared using the Gwet coefficient. Results:A total of 187 patients with 187 CRMs were enrolled in the study. The results of the classification of Bosniak Ⅱ, ⅡF, and Ⅲ CRMs categorized by 2 radiologists without and with subtraction images showed that 119 and 141 cases were consistent, and 68 and 46 were inconsistent, respectively. The weighted Kappa value for interobserver agreement among two radiologists without and with subtraction MR images was 0.60 (95%CI 0.53-0.68) and 0.73 (95%CI 0.66-0.80), respectively. The interobserver agreement was higher with subtraction images than that without subtraction images ( t=-2.56, P=0.011). Conclusion:According to the MRI criteria of Bosniak classification version 2019, the interobserver agreement for Bosniak Ⅱ, ⅡF, and Ⅲ CRMs could be improved using subtraction MR images, which may facilitate the popularization and application of Bosniak classification version 2019.

Objective:To analyze the MRI characteristics of surgical resected renal angiomyolipoma (AML) smaller than 4 cm.Methods:A total of 112 patients with surgical pathology confirmed renal AML of which the maximum diameter was smaller than 4 cm were analyzed retrospectively in the First Medical Centre, Chinese PLA General Hospital from January 2014 to November 2020, 5 of which were epithelioid angiomyolipoma (EAML) patients. According to the presence or absence of visible fat in lesions on MRI, the lesions were divided into AML with fat group and AML without visible fat (AML wovf) group. The MRI features were evaluated, including maximum diameter, location, growth pattern, shape, beak sign, angular interface with renal parenchyma, pseudo-capsule, hemorrhage, cystic degeneration, coagulative necrosis, flowing void in the tumor, signal intensity and homogeneity on T 2WI and diffusion weighter imaging (DWI), the peak enhanced phase. The differences of maximum diameter of AML with fat and AML wovf were analyzed using Mann-Whitney U test, and the differences of MRI features were analyzed using χ 2 test or Fisher′s exact probability test. Results:There were 123 lesions found in 112 patients, and 96 lesions contained fat and 27 lesions were AML wovf. 82 lesions showed round and round-like shapes, 112 lesions showed exophytic growth pattern, 71 lesions with peak enhancement in corticomedullary phase. And the numbers of lesions with angular interface with renal parenchyma, beak sign, cystic degeneration, pseudo-capsule, hemorrhage were 30, 49, 1, 1, 1, respectively. There was no coagulative necrosis in all lesions. Compared with AML with fat, AML wovf was single lesion. The diameters of AML with fat and AML wovf were 2.5 (1.7, 3.5) and 1.8 (1.4, 2.3) cm respectively, with statistically significant difference ( Z=-2.80, P=0.005). In the AML with fat and AML wovf, 65 and 12 cases were heterogeneous in T 2WI, 44 and 5 lesions showed beak sign, 26 and 4 lesions showed angular interface with renal parenchyma, 57 and 10 cases were heterogeneous in DWI. And there were 5 and 6 lesions showed the endophytic, 44 and 8 lesions showed partly exophytic, 47 and 13 lesions showed exophytic in patterns of tumor growth respectively. The beak sign, homogeneous in T 2WI and DWI, patterns of tumor growth showed statistical differences in AML with fat and AML wovf (all P<0.05), and there was no significant difference in other features ( P>0.05). A total of 5 EAML patients were with 8 lesions. One patient had 4 lesions with fat, other patients had single lesion in which 2 lesions with fat, 2 lesions without visible fat. One lesion without visible fat showed hemorrhage. Conclusions:Surgical resected AML smaller than 4 cm is often exophytic round and round-like, enhanced in corticomedullary phase, showing angular interface with renal parenchyma and beak sign, with rare cystic degeneration, pseudo-capsule, hemorrhage and improbable coagulation necrosis. AML wovf is single smaller lesion which often shows endophytic growth pattern, and beak sign is infrequent. EAML seems to be present in two modes, multiple lesions with fat and AML wovf with hemorrhage.

Objective:To investigate the clinical and MRI features of the mixed epithelial and stromal tumor family (MESTF) of the kidney.Methods:From January 2009 to September 2021, 42 patients with pathologically-proven MESTF from the First Medical Center of Chinese PLA General Hospital were collected in this retrospective study. Clinical information, MRI features, and pathological results were documented. According to the Bosniak classification (BC) version 2019, all MESTFs were divided into cystic MESTFs (36 cases) and solid-cystic MESTFs (6 cases). The R.E.N.A.L. nephrometry score (RNS), lesion size, laterality, location, margin, shape, growth pattern, presence of protruding into renal sinus, hemorrhage, and enhancement pattern were evaluated and documented. Based on BC versions 2005 and 2019, all the cystic MESTFs were assessed and divided into low (Ⅰ, Ⅱ, ⅡF) and high (Ⅲ, Ⅳ) grades. The independent sample t test or Mann-Whitney U test were performed to compare age, RNS, and lesion size between cystic MESTFs and solid-cystic MESTFs. Pearson χ 2 test, continuity-adjusted χ 2 test or Fisher exact probability test were utilized to evaluated the differences of clinical and MRI features and the distribution of low or high grades in two versions of BC. Results:Forty-two MESTFs were unilateral and solitary masses, 25 males and 17 females, with a mean age of (41±13) years old. Compared to solid-cystic MESTFs, cystic MESTFs were prone to demonstrate endophytic growth pattern (χ 2=17.77, P<0.001), and no significant differences in other clinical and MRI features were observed between cystic and solid-cystic MESTFs (all P>0.05). There were 7 low-grade and 29 high-grade tumors in the BC version 2005, respectively. Meanwhile, 24 low-grade and 12 high-grade tumors in the BC version 2019, respectively. The distribution of low or high-grade tumors in the two versions of BC had a statistically significant difference (χ 2=16.37, P<0.001). Conclusion:MESTFs demonstrated middle-age onset and no gender predilection. Cystic MESTFs are more likely to exhibit endophytic growth pattern with low-grade classification in BC system version 2019.

Objective:To evaluate the clinical efficacy of A-PRF in the preservation of alveolar ridge after tooth extraction.Methods:Electronic databases of VIP,CNKI,Wanfang,CQVIP,Medline,Pubmed and Cochrane library were searched.The meta-analysis was performed by using Revman 5.4.Results:5 RCTs including 217 patients were identified.A-PRF can significantly reduce the vertical bone absorption of the extraction socket,can increase the amount of new bone formation in the extraction socket(P＜0.05).However,A-PRF can not effectively reduce the horizontal bone absorption and can not improve the bone density in the extraction socket(P＞0.05).Conclusion:A-PRF is effective in the alveolar ridge preservation after tooth extraction.

Objectives:To investigate the effects of sarcopenia on the clinical efficacy of percutaneous ver-tebral augmentation(PVA)in the treatment of osteoporotic thoracolumbar vertebral compression fracture(OTLVCF).Methods:We retrospectively analyzed the clinical data of 270 patients with OTLVCF who under-went PVA in the Second Affiliated Hospital,Air Force Military Medical University and Honghui Hospital Af-filiated to Xi'an Jiaotong University from January 2020 to December 2022.There were 109 males and 161 females;T10 vertebral fracture in 37 cases,T11 fracture in 52 cases,T12 fracture in 68 cases,L1 fracture in 72 cases,and L2 fracture in 41 cases.The patients were divided into sarcopenia group(52 cases)and non-sarcopenia group(218 cases)according to the diagnostic criteria of the European Working Group on Sar-copenia in Older People(EWGSOP),and using the dominant hand grip strength(＜28.0kg)and the skeletal mus-cle index(SMI)at L3 level(＜45.4cm2/m2)in male and the dominant hand grip strength(＜18.0kg)and SMI at L3 level(＜34.4cm2/m2)in female as the diagnostic thresholds.The general data(gender,age,height,weight,body mass fraction,fracture segment,strength of grasp and skeletal muscle index),operative data(surgical method,operative time,intraoperative blood loss,bone cement injection volume and intraoperative fluoroscopy times),and complications(cement leakage,refracture of injured vertebra,refracture of the adjacent vertebra and distal vertebral refracture)after operation of both groups of patients were collected.The visual analogue scale(VAS)and Oswestry disability index(ODI)were collected before operation and on postoperative 1d,at 1 month,6 months and 1 year postoperatively and compared between the two groups.Results:There was no statistical difference in gender,height,weight,operative method,operative time,blood loss,bone cement injection vol-ume,intraoperative fluoroscopy times,and preoperative VAS score and ODI between the two groups(P＞0.05).The patients in the sarcopenia group were older(80.3±7.9 years vs 75.7±6.8 years,P＜0.05)and had a smaller BMI(24.4±2.2kg/m2 vs 26.2±2.4kg/m2,P＜0.05).The VAS score and ODI of the two groups on ld and,at 1 month,6 months and 1 year after operation were significantly improved compared with those before operation(P＜0.05).At the same time,the VAS score and ODI in the sarcopenia group were significantly higher than those in the non-sarcopenia group on ld and,at 1 month,6 months and 1 year after operation(P＜0.05).In terms of complications,there was no significant difference in the incidence of bone cement leakage between the two groups(9.65％vs 7.34％,P＜0.05).The incidence of re-fracture of injured vertebrae,adjacent vertebrae and distal vertebrae and the total incidence of re-fracture within 1 year after operation in the sarcopenia group were significantly higher than those in the non-sarcopenia group(9.62％vs 2.75％,13.46％vs 5.05％,11.54％vs 4.13％and 33.61％vs 11.93％,P＜0.05).Conclusions:The clinical effects of vertebral augmenta-tion(PVA)in patients with sarcopenia are poorer than in non-sarcopenia OTLVCF patients,with higher verte-bral re-fracture rates within 1 year after operation.

Objective:To evaluate the efficacy of holographic image technology in robot-assisted laparoscopic radical prostatectomy (RARP).Methods:The clinical data of 34 patients with prostate cancer who underwent RARP in our hospital during October 2020 and December 2020 was analyzed retrospectively. The average age of the patients was 67.8 (52-78) years. The mean BMI was 25.8 (18.0-32.3) kg/m 2. The median level of PSA before surgery was 13.4 (2-149) ng/ml. Median prostate volume was 31.7 (9.5-159.1) ml. EAU risk groups for biochemical recurrence of localised and locally advanced prostate cancer were list as below: 5 cases of low-risk, 7 cases of medium-risk, 22 cases of high-risk. There were 9, 16, 9 cases with the ASA score of 1, 2, 3 point, respectively. Preoperative Gleason score of 34 patients were list as below: 9 cases in score ≤6 group, 15 cases in score=7 group, 10 cases in score ≥8 group. For clinical stage before the surgery, 13 cases ≤T 2a stage, 1 case in T 2b stage, 20 cases ≥T 2c stage. The engineers established holographic images of 34 patients based on multiparametric magnetic resonance imaging (mpMRI) and the reports before the operation. Surgeons can obtain the size and location of tumors, surrounding neurovascular bundles visually by revolving, assembling, disassembling and concealing images, which was helpful for pre-surgery planning. By manipulating the holographic images extracorporeally, surgeons can discriminate Internal sphincter of urinary bladder and vesicoprostatic muscle, neurovascular bundles, membranous part, seminal vesicle easily, which improves the operation accuracy. Results:All 34 cases underwent operation successfully without transferring to open surgery. The median operative time was 157.5 (95-276) min with an estimated blood loss of 50 (20-300) ml. The median drainage removal time was 2 d and median hospitalization time was 3.5 d, respectively. The catheters were removed within an average time of 20.5 d. For postoperative Gleason score, there were 2 cases in score ≤6 group, 16 cases in score =7 group, 8 cases in score ≥8 group and 8 cases can’t make a score. For clinical stage after the surgery, 10 cases were ≤T 2a stage, 1 case was T 2b stage, 23 cases were ≥cT 2c stage. 22 cases underwent pelvic lymph node dissection, including a patient with right iliac fossa lymph node metastasis. There were 2 cases with positive surgical margin and 3 cases with Clavien-DindoⅠcomplications. The rate of 1-month and 3-month urinary continence were 47.1% and79.4%, respectively, 8 cases recovered erectile function after 3 month. Conclusions:Holographic image technology can promote cancer dissection completely, achieve urinary continence early and reduce perioperative complications tremendously. The technology is the "intraoperative security" for the accurate surgical treatment of prostate cancer.

Objective:To evaluate the test-retest reliability of MRI criteria in the 2019 Bosniak classification of cystic renal masses (CRMs) and to analyze the impact of lesions′ property, size and readers′ experience on the test-retest reliability.Methods:From January 2009 to June 2019, 207 patients with 207 CRMs were included in this retrospective study. All of them underwent renal MRI and surgical-pathologic examination. According to Bosniak classification, version 2019, all CRMs were independently classified twice by eight radiologists with different levels of experience. All radiologists were blinded to the pathology of the lesions. By using intraclass correlation coefficient (ICC), test-retest reliability was evaluated for all CRMs and for subgroups with different pathological properties (benign and malignant) and different sizes (≤40 mm and>40 mm). The test-retest reliability of 4 senior readers (≥10 years of experience) and 4 junior readers (<10 years of experience) were evaluated respectively. The comparison of ICC was performed using Z test. Results:The 207 CRMs included 111 benign lesions (83 benign cysts, 28 benign tumors) and 96 malignant tumors. There were 87 lesions with maximum diameter ≤40 mm and 120 with maximum diameter>40 mm. The test-retest reliability (ICC) of each reader for all lesions was 0.776-0.888, the overall ICC was 0.848 (95%CI 0.821-0.872). The ICCs of senior and junior readers were 0.853 (95%CI 0.824-0.880) and 0.843 (95%CI 0.811-0.871) respectively, without significant difference between the two groups ( Z=0.85, P=0.374). The ICC of all readers was 0.827 for benign lesions and 0.654 for malignant lesions, showing significant difference ( Z=2.80, P=0.005). The ICC was 0.770 for lesions ≤40 mm and 0.876 for lesions>40 mm, which was significantly different ( Z=-2.36, P=0.018). For CRM subgroups with different pathological properties and different sizes, there was no significant difference in test-retest reliability between senior and junior readers (all P>0.05). Conclusion:The test-retest reliability of MRI criteria in the 2019 Bosniak classification of CRMs is excellent and unaffected by readers′ experience. The reliabilities are not consistent among CRMs of different pathological properties and different sizes, but all reached the level of good and above.

【Objective】 To compare the clinical efficacy of unilateral biportal endoscopic （UBE） and microscopic discectomy in the treatment of lumbar disc herniation （LDH） and to explore the safety and effectiveness of this operation. 【Methods】 A total of 87 LDH patients from July 2018 to July 2021 were analyzed retrospectively， including 42 cases of unilateral biportal endoscopic discectomy and 45 cases of microscopic discectomy. Analysis was based on comparison of perioperative metrics， operation time， and estimated blood loss. Clinical outcomes were evaluated using visual analogue scale （VAS）， Oswestry disability index （ODI） and modified Macnab criterion. 【Results】 All patients were followed up for 13.3±1.18 months. In UBE group， operation time （57.12±6.35） min was shorter than that in the microscope group （62.21±7.09） min and estimated blood loss （29.31±3.62） mL was smaller than that in the microscope group （51.77±8.43） mL， with a significant difference （P<0.05）. The two groups of patients had significantly lower back pain VAS score， leg pain VAS score， and ODI index than those before operation （P<0.05）. The VAS score of lower back pain at 3 days after operation and the ODI index at 1 month after operation were significantly lower in UBE group than in the microscope group （P<0.05）. At other time points， there was no significant difference in lower back pain VAS score， leg pain VAS score or ODI index （P>0.05）. Dural sac tear occurred in 2 cases in UBE group and 3 cases in the microscope group； the incidence was not statistically significant （P>0.05）. Modified MacNab criterion evaluation at the last follow-up showed that 32 cases were excellent in UBE group， 7 cases were good， and 3 cases were fair， with the excellent and good rate of 92.9% （39/42）. The microscope group was excellent in 31 cases， good in 10 cases， and fair in 4 cases， with the excellent and good rate of 91.1% （41/45）. 【Conclusion】 UBE for LDH has a satisfactory short-term clinical efficacy， with the advantages of less trauma， greater efficiency， clear vision， and large operating space. Both UBE and microscopic discectomy can achieve good clinical results in treating LDH， but the former has the advantages of less trauma， high efficiency， and quick postoperative recovery.