Purpose To evaluate the image quality improvement of deep learning iterative reconstruction(DLIR)on pediatric head CT images of head injury and to evaluate the performance of DLIR and conventional adaptive statistical iterative reconstruction-veo(ASIR-V)of noise and image texture of CT image in children's head trauma.Materials and Methods A total of 80 cases in Beijing Children's Hospital,Capital Medical University from December 7th to 11th 2020 of children's head low-dose CT were retrospectively selected.Scan voltage was 120 kV.Scan current was 150-220 mA.The raw data were reconstructed into 5 mm thick slice and 0.625 mm thin slice brain window and bone window images.50%ASIR-V and high weight DLIR images(DL-H)were reconstructed,respectively.A 4-point system was used to subjectively evaluate the display of sulcus,brain matter and bone.The number of lesions in each group was counted.The CT value and image noise values of gray matter and white matter were measured,and the contrast to noise ratio was calculated,then measured the blur metric index was measured in the same slice.The differences between the two image reconstruction methods were compared.Results Compared to 50%ASIR-V images,DL-H significantly improved the display ability of the sulcus and ventricles,as well as the display ability of the brain parenchyma(W=5.5-22.2,all P<0.05)in both slice thickness.There was no statistically significant difference in the display ability of the sulcus and ventricles between 5 mm 50%ASIR-V and 0.625 mm DL-H images(W=0.9,2.0,P=0.32,0.05,respectively).In terms of bone display ability,all images could achieve a maximum score of 4.0.A total of 35 lesions were found in 80 patients via 5 mm 50%ASIR-V and DL-H images,including 12 hemorrhagic lesions,1 intracranial gas,9 fractures,and 13 soft tissue swelling.In terms of objective evaluation,the noise level of DL-H images was significantly lower than that of 50%ASIR-V images(t=21.4-35.7,all P<0.05),and there was no statistically significant difference in noise and contrast noise ratio between 5 mm 50%ASIR-V and 0.625 mm DL-H images(t=1.7-2.2,all P≥0.05).The blur metric index showed that DL-H was superior to 50%ASIR-V images(t=6.1,10.0,both P<0.05),and there was no statistically significant difference in blur metric index between 0.625 mm DL-H and 5 mm 50%ASIR-V images(t=2.6,P=0.28).Conclusion DLIR can improve the CT image quality and image texture of children's head trauma,0.625 mm DL-H image quality is close to 5 mm 50%ASIR-V image,which can meet the diagnostic requirements,and possible to further reduce the radiation dose.

Objective:To understand the current situation of CT radiation dose in children all over our country, and to explore the diagnostic reference level (DRL) of CT in children.Methods:The radiation dose reports of pediatric CT examination were collected end to November 30, 2021 and divided into five age groups: 0-1 month,>1 month-4 years,>4-10 years,>10-14 years and >14-18 years. There were 9 scanning item such as head, nasal sinus, temporal bone, neck, chest, abdomen, head enhanced CT, chest enhanced CT and abdomen enhanced CT. In each item, volume CT dose index (CTDI vol) and dose length product (DLP) were selected as radiation dose parameters, the 75% percentile were selected for DRL. The DRL results of head, chest and abdomen were compared with the DRL published by Chinese Society of Radiology and European Commission. Results:From March 2019 to November 2021, a total of 33 hospitals in 23 provinces were collected, including 20 children′s specialized hospitals, 11 women′s and children′s hospitals and 2 general hospitals, including 19 135 children′s CT scans. The DRL of 45 subgroups according to 5 age groups and 9 scanning items were obtained. The DRL results showed that the CTDI vol in five age groups was 26.9-42.8 mGy, and the DLP was 347-694 mGy·cm for head; 3.5-8.0 mGy, 54-293 mGy·cm for chest; and 6.3-13.2 mGy, 155-564 mGy·cm for abdomen. The DRL of the age group >4-10 years group in this investigation was agreed to the DRL of Chinese Society of Radiology. Compared with the European guidelines, there was little difference in the radiation dose of head scan, while the radiation dose of chest and abdomen in the young age group increased significantly. Conclusion:This survey reveals the radiation dose level distribution of children CT in our country. The radiation dose level of some items was inconsistent with the DRL of relevant international organizations. So our own DRL is needed to be set up according to the actual clinical reality of our country as a guideline.

Objective:Gasless laparoscopic surgery using lifting device was first introduced in 1993 mainly for general surgery and gynecology. Here we report its application in bifid rib treatment and explore the feasibility and safety of the surgery.Methods:From July 2008 to December 2019, according to the enrollment criteria, 278 patients of bifid ribs were treated at the Department of Thoracic Surgery, Beijing Children’s Hospital, Capital Medical University, including 183 males and 95 females, the mean age was(5.7±2.5) years old. There were 242 cases of single bifid rib and 36 cases of multiple bifid ribs. The bifid ribs were more common on the right side, as 184 cases had bifid ribs on right side, while only 68 cases on the left side and 26 cases on both sides. Patients’ clinical data were retrospectively summarized and analyzed, including the patients’ gender, age, location and type of bifid rib, perioperative outcome, and follow-up.Results:All the 278 patients successfully completed the operation. The abnormality was most frequently found in the fifth rib(incidence ranking: fifth > fourth > third > sixth). The mean operation time was(64.5±16.1)min, and the mean blood loss was(4.8±2.1)ml. No serious complications occurred during the surgery. Follow-up was done for 7 to 120 months, and no recurrent patients were observed.Conclusion:Gasless endoscopy with lifting device has been used as a safe and effective method to treat bifid ribs in our hospital. This surgery leads to less injury, smaller incision, and no scars on the front chest. Gasless endoscopic surgery with lifting device can be one of the options for correcting bifid ribs.

Objective:To investigate the clinical efficacy of TiRobot-assisted minimally invasive percutaneous screw fixation for pelvic fractures.Methods:The clinical data of 44 patients with pelvic fracture were retrospectively analyzed who had undergone TiRobot-assisted minimally invasive percutaneous screw fixation from May 2018 to April 2021 at Department of Orthopedic Traumatology, The First Hospital of Jilin University. There were 30 males and 14 females, aged from 11 to 78 years (average, 40.6 years). According to the Tile classification, there were 20 type C1 fractures, 23 type C2 fractures and one type C3 fracture. The time from injury to operation averaged 8.2 days (from 1 to 41 days). The minimally invasive percutaneous screw fixation was assisted by the orthopaedic TiRobot in all patients. Operation time, fluoroscopy time, reduction quality, complications and functional recovery at the final follow-up were recorded and analyzed.Results:A total of 96 screws were implanted in this cohort. The total fluoroscopy time ranged from 17 to 66 s, with an average of 17.8 s for each single screw. The operation time ranged from 50 to 355 min, averaging 179.7 min. According to the Matta criteria, the reduction quality was rated as excellent in 36 cases, as good in 5 and as fair in 3, yielding an excellent and good rate of 93.2%(41/44). All the 44 patients were followed up for 6 to 42 months (average, 20.4 months). The fracture healing time ranged from 2 to 6 months, averaging 3.3 months. The Majeed scores at the final follow-up ranged from 51 to 100 points (average, 83.7 points); there were 28 excellent, 8 good, 7 fair and one poor cases, giving an excellent to good rate of 81.8% (36/44). Follow-up found no such complications as iatrogenic neurovascular injury, incision infection, malunion, implant loosening or fracture re-displacement in all the 44 patients.Conclusion:TiRobot-assisted minimally invasive internal fixation can result in fine clinical efficacy for pelvic fractures, showing advantages of accuracy, minimal invasion and safety.

Objective:To demonstrate whether image quality and measurement accuracy of vessel wall thickening could be improved using a deep learning image reconstruction (DLIR) algorithm in children with Takayasu arteritis.Methods:From September 2019 to April 2020, 32 patients with Takayasu arteritis underwent low-dose contrast-enhanced CT with 100 kVp in Beijing Children′s Hospital were enrolled retrospectively. The raw data were reconstructed at 0.625 mm slice thickness using the filtered back projection (FBP), 50% adaptive statistical iterative reconstruction-V (ASIR-V) at 50% (50%ASIR-V), ASIR-V at 100% (100%ASIR-V) and DLIR. Subjective evaluation including the image quality of vessel wall identification, overall image noise and diagnostic confidence were evaluated using a 5 points scales by 2 observers. Objective evaluation including the thickness and standard deviation of vessel wall were measured, then the coefficient of variation (CV) was calculated. The CT value and noise of aorta were measured to calculate the contrast to noise ratio (CNR) of image. Friedman test was used to compare the differences of subjective scores among the four groups, and the analysis of variance of random blocks was used to compare the differences of objective measurement indices.Results:In terms of subjective score results, there was no significant difference between 100%ASIR-V and DLIR of overall image noise ( P>0.05), and the image scores of the two groups were higher than those of FBP and 50%ASIR-V (all P<0.05). The vessel wall identification and diagnostic confidence of DLIR were higher than those of other images (all P<0.05). The objective measurement results showed that the standard deviation and CV of vessel wall thickness in DLIR were significantly lower than those in other images (all P<0.05). There was no significant difference in vascular noise, muscle noise and CNR between 100%ASIR-V and DLIR (all P>0.05), which were lower than those in FBP and 50%ASIR-V (all P<0.05). Compared with 50%ASIR-V, the CV of DLIR was reduced by 22.9%, and the CNR was increased by 46.8%. Conclusion:DLIR can improve the overall image quality of CECT in children with Takayasu arteritis and the measurement accuracy of vascular wall, making it possible to further reduce the radiation dose.

Objective:To evaluate clinical characteristics and treatment of postoperative anastomotic stricture in pediatric congenital biliary dilatation patients.Methods:The clinical data of 24 children with postoperative anastomotic stricture from Apr 2012 to Oct 2019 in Beijing Children's Hospital was retrospectively analyzed.Results:There were 6 males and 18 females. Patients were divided into bile- leak group (BL, n=6) and non bile-leak group (NBL, n=18) based on whether there was anastomotic leakage after primary surgery. The main symptoms in BL group was persistent obstructive jaundice, and recurrent cholangitis in NBL group. Postoperative symptoms were first shown in an average of 7.0 months in BL group, compared to 59.0 months in NBL group, P<0.05. In BL group, 4 underwent redoing hepaticojejunostomy, 2 underwent anastomosis plasty. In NBL group, 3 underwent redoing hepaticojejunostomy, 15 did anastomosis plasty with multiple biliary stones found necessitating extraction. After reoperation, one patient had bile leakage, 2 patients had recurrent cholangitis within one-month, 21 patients had uneventful recovery. Five were found to have biliary stones in long-term follow-up. Conclusions:Biliary-enteric anastomotic leakage can cause stricture in postoperative patients of congenital biliary dilatation ,reoperation is necessary in symptomatic patients.

OBJECTIVES: To explore the risk factors for femoral neck fracture in elderly population. METHODS: A total of 124 elderly patients (≥60 years old) in hospital for trauma were enrolled, including 71 patients (57%) with femoral neck fracture and 53 non-femoral neck fracture patients (43%). All patients' age, gender, body mass index (BMI), bone mineral density (BMD), thigh length and average circumference were collected. Single factor analysis and multivariate logistic regression analysis were performed to explore whether the above factors were risk factors for femoral neck fracture. RESULTS: Single factor analysis showed that the age, gender, BMI, BMD, thigh length, and average thigh circumference between the 2 groups were statistically different (all CONCLUSIONS Older age, female, lower BMI index (low body weight), lower BMD (osteoporosis), longer thigh length, and lower average circumference are risk factors for femoral neck fracture in the elderly population.
Absorptiometry, Photon ; Aged ; Body Mass Index ; Bone Density ; Female ; Femoral Neck Fractures/etiology* ; Humans ; Middle Aged ; Osteoporosis ; Risk Factors

Objective:To investigate the feasibility, clinical efficacy and safety of endobronchial ultasound (EBUS) in children.Methods:The radiological features, EBUS images, pathological results and intraoperative and postoperative complications of 3 cases who underwent EBUS examination and 1 case who underwent EBUS guided transbronchial needle aspiration (EBUS-TBNA) were retrospectively analyzed.Results:Among the 4 cases, 2 were males and 2 were females, with the onset age of 7.4-9.2 years. The child who underwent successful EBUS-TBNA was presented with fever and diagnosed with mediastinal lymphadenopathy before the operation, and the postoperative pathology indicated histiocytic necrotic lymphadenitis (HNL). The other 3 children diagnosed with primary airway tumors, whose pre-operative CT imaging found no infiltration in extra-bronchial structures, had the masses resected through EBUS. According to postoperative pathological findings, two were diagnosed with mucoepidermoid carcinoma and one with bronchial leiomyoma. The lesions were located at the opening of the right main bronchus in 1 case and at the main airway in 2 cases. EBUS showed abnormal echogenicity of the tracheal wall in the 3 cases, including hyperechoic area in the water capsule and mucous layer, relatively hypoechoic area in the submucosal smooth muscle layer, hyperechoic area in the inner cartilage layer, hypoechoic in the cartilage layer and hyperechoic in the outer cartilage layer. In one case, structural disorder of the submucosal smooth muscle layer and partial disruption of the cartilage layer of the tracheal wall were found at the lesion site, while the other 2 cases had intact tracheal wall structure. There were no postoperative complications such as pneumothorax or hemoptysis in the 4 children.Conclusion:EBUS is a safe and feasible technique for evaluating mediastinal lymph node enlargement and the degree of airway wall infiltration in primary airway tumor.

Objective:To explore the surgical effect and experience of endoscope-assisted excision for congenital nasal dermoid and sinus cyst (NDSC) in children.Methods:Fifty-three patients with congenital NDSC treated in Beijing Children′s Hospital from January 2007 to December 2018 were retrospectively reviewed, including 30 boys and 23 girls, with the age ranging from 9 to 145 months (mean age 35.6 months). The ultra-low-dose CT scan and MRI of the paranasal sinuses were performed for all patients. Excisions of NDSC under general anesthesia were performed for all patients, and surgical approaches were dependent on location and extent of the lesions according to radiographic workups. All intra-osseous patients and complicated superficial cases underwent surgical excision of NDSC and nasal reconstruction with the assistance of endoscope. Initial presentation, medical history, imaging workups, surgical approaches, complications, rates of recurrence and cosmetic outcomes were evaluated. Descriptive statistics was used for the results analysis.Results:Among 53 cases, the most common presentation included a nasal-glabella mass ( n=21, 39.6%), a dorsal punctum ( n=13, 24.5%) and a dorsal mass ( n=9, 17.0%). The sites of NDSC included nasal glabella ( n=22, 41.5%), nasal bridge ( n=27, 50.9%) and nasal tip ( n=4, 7.5%). Of all patients, 24 cases (45.3%) had superficial lesions, 19 cases (35.8%) had intraosseous extension into the frontonasal bones, 10 cases (18.9%) extended intracranially but remained extradural. Surgical approaches included transverse incision ( n=22, 41.5%), minimal midline vertical incision ( n=27, 50.9%) and external rhinoplasty ( n=4, 7.5%). All NDSC were successfully excised and no nasal reconstruction needed. All cases were followed up from 9 to 151 months with a mean of 67.3 months. Five patients (9.4%) with recurrence were observed and were managed successfully with reoperation. During the follow-up, no nasal deformity was noted, and cosmetic outcome was favorable for all patients. Conclusion:Endoscope-assisted excision has the advantage of clear vision, small trama and low recurrence rate for children with NDSC.

Objective: To provide data references for Nuss procedure biomechanics research, and to understand morphological pathological changes in children with pectus excavatum. Methods: A retrospective study was conducted for 434 cases of pectus excavatum from January 2009 to December 2015 in our institution. The anterior rib width(RW), anterior intercostal space width(IS) and thickness of the rib in the middle(RT) on the right side of 3-7 ribs had been measured in each patient. The widths were compared between the IS of children with pectus excavatum and the bar which currently used in clinic. The measurement indexes were compared between healthy children and children with pectus excavatum. Results: The IS of prepubertal children with pectus excavatum was less than the width of bar which currently used in clinic (12.7 mm). Children with pectus excavatum compared with healthy children, the IS from 4 to 6 and the 5th RW of children with pectus excavatum were less than healthy children (P<0.05), the 3rd and 4th RT were greater than healthy children (P<0.05). Conclusion The measured values will be useful for the improvement of pectus bar and Nuss procedure biomechanics research. By morphology contrast, it reflects the pectus excavatum deformity has some restriction in thoracic development and the cardiopulmonary function.