Objective To investigate the imaging features of Langerhans cell histiocytosis(LCH)in the long bones of the limbs in children.Methods The clinical and imaging data of 23 children with long bones of the limbs were analyzed retrospectively.X-ray examinations were performed in 21 cases,CT scans in 16 cases,and MRI scans in 19 cases.Results The lesions were located in femur in 14 cases,tibia in 3 cases,fibula in 2 cases,humerus in 1 case,ulna in 2 cases,and both tibia and fibula in 1 case.Lesions were found in the diaphysis in 16 cases and the metaphysis in 7 cases(involving the epiphysis in 2 cases).Bone destruction appeared as oval,irregular,or eccentric shapes,with clear boundaries in 17 cases,blurred boundaries in 6 cases,and sclerosis in 6 cases.The average CT value was(48.27±8.20)HU,with"gear-like"changes in the axial view in 10 cases."Sleeve-like"periosteal reaction was observed in 14 cases,localized periosteal reaction in 5 cases,and no periosteal reaction in 4 cases.The lesions showed iso-or slightly hypointense signals on T1 WI,hyperintense signals on T2 WI,and hyperintense signals on diffusion weighted imaging(DWI),with an average apparent diffusion coefficient(ADC)value of(1.26±0.17)×10-3 mm2/s.Soft tissue masses were found in 7 cases.After enhancement,moderate to marked enhancement was observed in 9 cases,with lace-like enhancement in 6 cases.Among the 17 cases followed up,13 cases returned to normal or had only residual bone cortical thickening,3 cases showed a reduction in lesion size,and 1 case died.Conclusion The imaging features of LCH in the long bones in children have certain characteristics,but can still be easily confused with infections or malignant bone tumors.A comprehensive analysis combining clinical and imaging features is necessary to improve diagnostic accuracy.

Objective To explore the application and clinical significance of prenatal MR in the diagnosis of fetal micrognathia and associated malformations.Methods A retrospective analysis was conducted on 30 pregnant women who underwent fetal MR exami-nation.Twelve fetuses with micrognathia were included in the case group,and 18 fetuses with normal mandibles were included in the control group.The fetal inferior facial angle(IFA)was measured,pregnancy outcomes were followed up,and receiver operating characteristic(ROC)curve analysis was performed.Results There was no correlation between IFA measured by fetal MR and gesta-tional age(P＞0.05).The area under the curve(AUC)of IFA in the diagnosis of micrognathia was 0.931,with a sensitivity of 88.9％,a specificity of 83.3％,and a cutoff value of 51.95°.Conclusion Prenatal MR has diagnostic significance in the diagnosis of fetal microg-nathia and associated malformations.It is suggested that IFA＜51.95°should be used as a positive diagnostic criterion for microg-nathia.The measurement of IFA by fetal MR provides high accuracy and valuable reference for the diagnosis of fetal micrognathia.

This report described the multidisciplinary management of a preterm infant with congenital tracheal agenesis (TA). The infant, delivered via cesarean section at 32 +5 weeks' gestation, had Apgar scores of 6 and 8 at 1 and 5 minutes, respectively. Although skin color improved after 30 seconds of bag-mask ventilation, the infant exhibited no cry, weak spontaneous breathing, and failed multiple intubation attempts. The patient was transferred to Anhui Children's Hospital of Fudan University under continuous bag-mask positive-pressure ventilation at 3 hours after birth (September 10, 2024). Combined imaging and fiberoptic bronchoscopy confirmed TA (Floyd type Ⅱ/Faro type C) with multiple anomalies, including duodenal atresia, aortic coarctation, and butterfly vertebrae. Whole-genome sequencing revealed a suspected mosaic SCN2A c.5317G>A variant (wild-type parents) and an ERCC5 c.2974C>T heterozygous variant inherited from the mother (homozygous). Following esophageal intubation, invasive mechanical ventilation, and continuous gastrointestinal decompression, respiratory distress significantly improved with a stabilized condition. The infant died 30 hours after birth following treatment withdrawal.

Objective To investigate the imaging features of Langerhans cell histiocytosis(LCH)in the long bones of the limbs in children.Methods The clinical and imaging data of 23 children with long bones of the limbs were analyzed retrospectively.X-ray examinations were performed in 21 cases,CT scans in 16 cases,and MRI scans in 19 cases.Results The lesions were located in femur in 14 cases,tibia in 3 cases,fibula in 2 cases,humerus in 1 case,ulna in 2 cases,and both tibia and fibula in 1 case.Lesions were found in the diaphysis in 16 cases and the metaphysis in 7 cases(involving the epiphysis in 2 cases).Bone destruction appeared as oval,irregular,or eccentric shapes,with clear boundaries in 17 cases,blurred boundaries in 6 cases,and sclerosis in 6 cases.The average CT value was(48.27±8.20)HU,with"gear-like"changes in the axial view in 10 cases."Sleeve-like"periosteal reaction was observed in 14 cases,localized periosteal reaction in 5 cases,and no periosteal reaction in 4 cases.The lesions showed iso-or slightly hypointense signals on T1 WI,hyperintense signals on T2 WI,and hyperintense signals on diffusion weighted imaging(DWI),with an average apparent diffusion coefficient(ADC)value of(1.26±0.17)×10-3 mm2/s.Soft tissue masses were found in 7 cases.After enhancement,moderate to marked enhancement was observed in 9 cases,with lace-like enhancement in 6 cases.Among the 17 cases followed up,13 cases returned to normal or had only residual bone cortical thickening,3 cases showed a reduction in lesion size,and 1 case died.Conclusion The imaging features of LCH in the long bones in children have certain characteristics,but can still be easily confused with infections or malignant bone tumors.A comprehensive analysis combining clinical and imaging features is necessary to improve diagnostic accuracy.

Objective To explore the application and clinical significance of prenatal MR in the diagnosis of fetal micrognathia and associated malformations.Methods A retrospective analysis was conducted on 30 pregnant women who underwent fetal MR exami-nation.Twelve fetuses with micrognathia were included in the case group,and 18 fetuses with normal mandibles were included in the control group.The fetal inferior facial angle(IFA)was measured,pregnancy outcomes were followed up,and receiver operating characteristic(ROC)curve analysis was performed.Results There was no correlation between IFA measured by fetal MR and gesta-tional age(P＞0.05).The area under the curve(AUC)of IFA in the diagnosis of micrognathia was 0.931,with a sensitivity of 88.9％,a specificity of 83.3％,and a cutoff value of 51.95°.Conclusion Prenatal MR has diagnostic significance in the diagnosis of fetal microg-nathia and associated malformations.It is suggested that IFA＜51.95°should be used as a positive diagnostic criterion for microg-nathia.The measurement of IFA by fetal MR provides high accuracy and valuable reference for the diagnosis of fetal micrognathia.

This report described the multidisciplinary management of a preterm infant with congenital tracheal agenesis (TA). The infant, delivered via cesarean section at 32 +5 weeks' gestation, had Apgar scores of 6 and 8 at 1 and 5 minutes, respectively. Although skin color improved after 30 seconds of bag-mask ventilation, the infant exhibited no cry, weak spontaneous breathing, and failed multiple intubation attempts. The patient was transferred to Anhui Children's Hospital of Fudan University under continuous bag-mask positive-pressure ventilation at 3 hours after birth (September 10, 2024). Combined imaging and fiberoptic bronchoscopy confirmed TA (Floyd type Ⅱ/Faro type C) with multiple anomalies, including duodenal atresia, aortic coarctation, and butterfly vertebrae. Whole-genome sequencing revealed a suspected mosaic SCN2A c.5317G>A variant (wild-type parents) and an ERCC5 c.2974C>T heterozygous variant inherited from the mother (homozygous). Following esophageal intubation, invasive mechanical ventilation, and continuous gastrointestinal decompression, respiratory distress significantly improved with a stabilized condition. The infant died 30 hours after birth following treatment withdrawal.

Objective To explore the application value of polidocanol foam combined with absolute ethanol in the treatment of lower extremity venous malformation(VM)in children.Methods The clinical data of 20 children with lower extremity VM were analyzed retrospectively.All of these children were diagnosed with VM of lower extremity by MRI and were treated with digital subtraction angiography(DSA)guided percutaneous sclerotherapy.Different hardening agents were selected according to the classification,the size of the lesion range and the flow rate during the operation.The VM with small lesions range,shallow location and slower velocity were treated with polidocanol foam only,while the VM with larger lesion range and faster velocity were combined treated with abso-lute ethanol.Clinical symptoms and MRI were used to evaluate the curative effect one month after operation.Results Twenty chil-dren received sclerotherapy.After the treatment,15 cases were cured,3 cases showed significantly effective,and 2 cases were effec-tive.Some of the children had pain and swelling of different degrees within 48 hours after operation,who were given symptomatic treatment,and the symptoms disappeared in the short time.The skin of the lesion ulcerated in one case and the ulceration healed after treatment.Conclusion Polidocanol foam combined with absolute ethanol is safe and effective in the treatment of lower extremity VM in children,and the combination can improve the curative effect and reduce the occurrence of postoperative complications.

Objective To explore the possibility of MR Ti-mapping imaging technology to provide additional indicators for clinical quantitative evaluation of renal function in children with renal insufficiency.Methods A total of 13 children with renal insufficiency diagnosed and underwent renal function MRI examination were selected(renal insufficiency group),and 23 children with normal renal function were included as the control group.The difference of renal cortex T1 value between the control group and the renal insuffi-ciency group was compared,and the correlation between renal cortex T1 value and biochemical indexes such as serum creatinine(SCr)and cystatin C(CysC)in the renal insufficiency group was analyzed.Results There was significant difference in T1 value of renal cortex between the renal insufficiency group and the control group(P＜0.01).The correlation between T1 value of renal cortex and SCr and CysC in renal insufficiency group was higher(r=0.75,P＜0.01;r=0.68,P＜0.01).Conclusion MR T1-mapping technol-ogy can non-invasively monitor the renal function status of children with renal insufficiency,and has a suggestive value for clinical quantitative evaluation of renal function in children.

Objective To analyze the clinical and MRI images of testicular teratoma in children and to compare with pathological results.Methods The clinical and MRI data of 12 children with testicular teratoma confirmed by pathology were analyzed retrospec-tively.Results Of the 12 cases,6 cases were on the left testicle and 6 cases were on the right testicle.The clinical manifestations were all painless testicle enlargement.Of these,6 cases were accompanied by a slight increase of neuron-specific enolase,3 cases had increased alpha-fetoprotein(AFP),10 cases were mature teratoma,and 2 cases were immature teratoma.MRI findings showed that the lesions in 6 cases were cystic,with long T1 and T2 signals as the main signals,no reduction in lipid pressure image signals,no enhance-ment on the enhanced scan,and low signal on diffusion weighted imaging(DWI).The other 6 cases were cystic-solid lesions,mainly with mixed T1 and T2 signals,and showed uneven high signal on DWI.The cystic components were not enhanced on the enhanced scan,and the solid components were mildly to significantly enhanced.Among them,3 cases were accompanied by irregular flaky short T1 and long T2 signals,decreased lipid pressure image signals,1 case was accompanied by speckle long T1 and short T2 signals.And the envelope intact in all 12 cases.Conclusion The MRI findings of testicular teratoma in children are mostly cystic lesions,with few signs of fat and calcification,and no obvious invasion of peripheral structures.AFP examination is helpful for diagnosis.

Objective To explore the clinical application value of interventional embolization in the treatment of giant infant parotid hemangioma.Methods The clinical data of 17 cases of giant infant parotid hemangioma were analyzed retrospectively.All childrens were performed relevant preoperative examination and CT enhancement examination,with no absolute contraindications for the treat-ment.Interventional embolization was performed under static aspiration compound anesthesia,propranolol was given orally on the same postoperative day.One month after surgery,the clinical effect was evaluated according to the clinical symptoms and ultrasound examination.Results A total of 18 interventional embolization were performed on 17 childrens,who were followed up for 6 months after surgery.The tumor body shrank by more than 80％,after treatment,the child had a symmetrical facial face,no soft tissue rupture,and normal skin color with no impairment of the parotid gland and facial nerve function.Conclusion Interventional embolization is safe and effective in the treatment of giant infant parotid hemangioma,and can become one of the preferred treatment methods for giant infant parotid hemangioma.