nal abnormalities of pediatric heart diseases.

Objective To summarize imaging features of Kallmann syndrome (KS) in children and to improve diagnostic level of the disease.Methods The imaging manifestations of 13 patients with clinically proved KS were retrospectively studied.MRI of rhinencephalon and left wrist X-ray examinations were performed in all the 13 children.Ultrasound of abdomen and pelvis was implemented in the 8 of 13 patients.Results All the patients had abnormalities of olfactory system.Bilateral olfactory bulbs and tracts were absent in 9 patients.Unilateral olfactory bulbs and tracts were absent in 4 patients,in which contralateral olfactory bulbs and tracts were hypoplastic.These patients presented 2 aplastic,17 hypoplastic and 7 normal olfactory sulci.Anterior pituitary was hypoplastic in 3 patients.Bone age showed retardation in 6 of 13 patients.Bilateral testicles were small in all the 8 cases by ultrasound.Conclusions Aplastic or hypoplastic olfactory bulbs and tracts and sulci are seen in children with KS.Anterior pituitary dysplasia is present in part of patients and bone age backward happens in approximate half of the children.

Objective To assess the value of functional magnetic resonance urography (fMRU)for the unilateral renal function in children with hydronephrosis.Methods Fourteen children with congenital hydronephrosis (unilateral hydronephrosis in 1 2 cases,bilateral hydronephrosis in 2 cases)examined by fMRU in Beijing Children′s Hospital,Capital Medical University,were enrolled.In 7 patients of them,diuretic renal scintigraphy (DRS)was per-formed within 1 0 days before fMRU examination.The following parameters in fMRU,as renal parenchymal volume,volu-metric differential renal function (vDRF),Patlak,Patlak differential renal function (pDRF),index of glomerular filtra-tion rate (GFR)and differential renal function based on index of GFR (gDRF),were calculated and analyzed.Statisti-cal analysis was performed by using SPSS 1 3.0.Results In 7 cases whose fMRU and DRS were examined,the indexes of GFR obtained from fMRU and GFR from DRS were well correlated (r =0.892,P <0.001 )in 1 4 kidneys.The gDRF determined by 2 methods on the left kidneys[the average was(46.80 ±1 9.20)% and(45.1 8 ±20.29)%,respective-ly]had no significant difference (t =0.051 6,P =0.624),which was also highly correlated (r =0.91 2,P =0.004). In 1 2 cases with unilateral hydronephrosis,vDRF,pDRF,index of GFR and gDRF in hydronephrotic side[(43.54 ± 9.61 )%,(42.80 ±1 0.83)%,(38.56 ±29.23)mL/min,(38.37 ±1 3.61 )%]were all less than those in the con-tralateral side[(56.46 ±9.61 )%,(57.1 9 ±1 0.83)%,(57.02 ±26.22)mL/min,(61 .63 ±1 3.61 )%](t =2.326, 2.300,2.422,2.960;P =0.040,0.042,0.034,0.01 3).However,there was no statistical difference in both renal pa-renchymal volume and Patlak between the hydronephrotic and the contralateral side kidneys(t =1 .765,1 .450;P =0.1 05,0.1 75).Conclusions fMRU is a very valuable examination method in evaluating single kidney function in children with congenital hydronephrosis,and able to demonstrate that gDRF,indexes of GFR,vDRF and pDRF decrease in the hydronephrotic kidney.

Objective To investigate the diagnostic value of MRI in reversible splenial lesion syndrome (RESLES) in children.Methods The clinical and MRI imaging data of 14 cases of RESLES in children were retrospectively reviewed.There were 4 males and 10 females,aging 11 to 35 months.Average age was (20±3) months.MRI studies were conducted in all the cases.Two experienced doctors analyzed independently the images and reached consensus.Results Fourteen cases showed the single abnormal signal in the splenial of corpus callosum on the initial cerebral MRI.Lesions in 10 of 14 cases appeared as isointensity on T1WI,hypo-intensity in 4 cases.Lesions in 14 cases were appeared as hyper-intensity on T2WI,hyper-/slightly hyper-intensity on FLAIR T2WI.The lesions were round,oval or irregular,with fuzzy boundary.DWI showed round or oval high signal with clear boundary.No edema around the lesion and no occupying effect were detected.After treatment,8 of 14 cases were reviewed after 7-14 d,and the abnormal signal in the corpus callosum disappeared in 5 cases,while the range was significantly reduced in 3 cases.MRI were reexamined after 1-2 months in 5 cases,and the lesions disappeared in the corpus callosum.One case didn't have MRI examination again after treatment and the clinical symptoms disappeared.Conclusions The clinical manifestations of RESLES in children are lack of specificity.And the cerebral MRI imaging is characterized by the reversible solitary lesion of the splenium,which can provide a reliable basis for clinical diagnosis and prognosis.

Objective To analyze CT and MR features of malignant peripheral nerve sheath tumor (MPNST)of children. Methods Sixteen patients with histologically proven MPNST were retrospectively reviewed.There were 8 male and 8 female, ages from 0.3 to 11.0 years, and median age was 2.5 years. Sixteen cases were performed with CT plain scan, and eight cases with CT enhancement scans, and three with MR examination. The imaging data were analyzed by two highly experienced doctors and obtained agreements after mutual consultation. Results Among 16 cases, 3 cases were located at neck, 5 cases at waist and back,3 cases at abdominal and pelvic, 2 cases at foot, 1 case at left clavicle, 1 case at right mediastinum, 1 case at right orbit. Fifteen cases appeared as solid masses and 1 case showed a diffuse growth. CT plain scan showed 8 cases were solid-appearing masses and 7 cases were cystic-solid mass. Enhanced CT showed enhancement of solid component was moderate to marked and gradually delayed enhanced while cystic component had no any enhancement. One was located on the left side of the neck and appeared as diffuse growth. Two cases of solid mass type appeared as hypo-intensity on T1WI and hyper-intensity on T2WI, and obviously high signal intensity of cystic component on T2WI, and with significantly heterogeneous enhanced.One case with diffuse growth appeared as hypo-intensity on T1WI and slightly hyper-intensity on T2WI, and with significantly enhanced. Sixteen cases appeared as invasive growth, 11 caseswith multiple organic metastases and recurrences, and 4 cases with neurofibromatosis type I and scoliosis.Conclusion CT and MR appearances of MPNST have certain characteristic features, and can demonstrateaggressive performance and multiple organic metastases, which is helpful for definite diagnosis and treatment plan.

Objective To demonstrate the clinical and imaging features of extrarenal malignant rhabdoid tumor (MRT) outside the central nervous system(CNS) in children and to raise awareness of the disease.Methods A retrospective database review was made of 15 patients diagnosed with extrarenal MRT outside the CNS in Beijing Children's Hospital,Capital Medical University from April 2008 to February 2017.The ultrasound,CT and magnetic resonance imaging(MRI) examinations were performed in 12,10 and 7 cases,respectively,and the clinical and imaging features were analyzed.Results The 15 patients included 8 boys and 7 girls.The age at presentation varied from 11 days to 12 years and 9 months old with a median age of 4 years old.The primary tumors were predominant solid masses,most of which were irregular,with a length of 2.20-11.70 cm [(5.87 ± 2.57) cm].The primary tumors had variable locations,relatively tended to occur in the head and neck region (6 cases) and the mediastinum (4 cases).On ultrasound,11 cases of the tumors were heterogeneous,7 cases of the tumors were accompanied with cystic change,and the solid part was mainly hypoechoic.On CT,density of 6 cases of the tumors was uneven,3 cases presented cystic change,4 cases were with calcification,and the solid part had slightly low density,with enhancement of different degrees.On MRI,7 cases of tumors showed mixed signal,5 cases with cystic change of different degrees;the solid part mainly showed isointensity or slightly hypointensity on T1 weighted image and hyperintensity or slightly hyperintensity on T2 weighted image,with restricted diffusion and predominantly heterogeneous enhancement.Medical imaging showed definite hemorrhage within tumors in 5 patients,and metastases occurred in 6 patients at the time of diagnosis,the adjacent bone destruction occurred in 3 patients,and the tumor tissue of 3 patients extended into the spinal canal.Conclusion Extrarenal MRT outside the CNS is more common in preschool kids,most of which are large and heterogeneous solid masses,often with cystic change,sometimes with hemorrhage and calcification;the solid part with restricted diffusion and inhomogeneous enhancement.Some of the patients had metastasis and local invasion.

ObjectivesTo identify the related abnormalities of gray matter in pediatric patients with Tourette syndrome (TS) by using the optimized voxel-based morphometry (VBM).Methods Three dimensional T1WI was acquired in 31 TS children (28 boys,3 girts,mean age 8 years,range 4-15 years) and 50 age- and sex-matched controls on a 1.5 Tesla Philips scanner. Images were pre-processed and analyzed using a version of VBM 2 in SPM 2.The whole brain gray matter volume was compared between the study and control group by using t-test.Multivariate linear regression analysis was used for analyzing the correlation between the change of grey matter volume within each brain region (mm3 ) and YGTSS score and course of disease of TS patients.Statistical analyses were performed by using SPSS 13.0.ResultsUsing VBM,significant increases in gray matter volumes in left superior parietal lobule, right cerebellar hemisphere and left parahippocampal gyrus were detected in TS patients,and the volume changes were 4059,2126 and 84 mm3 ( t =3.93,3.71,3.58,P ＜ 0.05 ) respectively.Compared to the control group,decreased grey matter volumes were found in medulla and left pons,and the volume changes were 213 and 117 mm3( t =3.53,3.48,P ＜ 0.05 )respectively.Tic severity was not correlated with any volume changes of gray matter in brain (P ＞ 0.05,a small volume correction,KE ≥ 10 voxel).Tic course was negatively correlated with the gray matter volume of left parahippocampal gyrus ( Beta =- 0.391,P =0.039 ).ConclusionsUsing VBM technique,the gray matter abnormalities can be revealed in TS patients without obvious lesions on conventional MR imaging.The increasing volume of temporal and parietal lobes and cerebellar may be an adaptive anatomical change in response to experiential demand. The gray matter volume of the parahippocampal gyrus may be used as one potential objective index for evaluating the prognosis of TS.

Objective To discuss the imaging features of skeletal changes in children with Gaucher disease on X-ray and MRI images.Methods One hundred and nine children with Gaucher disease were enrolled in this study.They all received routine X-ray for spine with anterior-posterior(A-P)and lateral view and bilateral femurs with A-P view.Among them.18 patients received X-ray for pelvic with A-P view.14 patients received X-ray for left wrist with A-P view.and 14 patients received MRI scan for femur.The MRI scan included T1-weighted imaging,T2-weighted imaging and fat-suppressed T2-weighted imaging with short tau inversion recovery(STIR)sequence.The imaging features of the X-ray and MRI images were analyzed retrospectively.Results The most common feature is osteoporosis,which presented in 91 cases (83.5%).Besides this,decreased density of metaphysis occurred in 86 cases(78.9%).erlenmeyer flask deformity of metaphysis occurred in 89 patients(81.7%),thinner cortex occurred in 69 cases(63.3%),osteolytic destruction occurred in 31 cases(28.4%).pathological fractures occurred in 26 cases (23.9%),osteosclerosis occurred in 12 cases(11.0%).cystic degeneration of bone occurred in 16 cases (14.7%),and dislocation of the hip occurred in 4 cases.All 14 patients received MRI presented abnormal signals.Among them,4 patients presented low signal intensity both on T1-weighted and T2-weighted images in bone marrow;the other ten presented high signal intensity mixed in low signal intensity areas on T2-weighted and fat-suppressed T2-weighted images.Conclusions The imaging features of skeletal changes in children with Gaucher disease are of some characteristics,which could provide useful information for the clinical treatment.

Objective:To evaluate the application of amide proton transfer weighted (APTw) magnetic resonance imaging(MRI) for grading of brainstem glioma (BSG) in children.Methods:Twenty-five children (16 males and 9 females) aged 0.7-12.4(5.6±3.3)years were diagnosed as BSG by surgery or biopsy in Beijing Children′s Hospital from December 2019 to March 2022, including 13 cases of low-grade BSG and 12 cases of high-grade BSG. APTw imaging and conventional MRI were performed on a 3.0 T MRI scanner. The differences in gender distribution, age, conventional MRI appearance, APTw signal intensity and apparent diffusion coefficient (ADC) between children with high and low grade BSG were analyzed. Receiver operating characteristic (ROC) curve was used to analyze the efficacy of APTw signal intensity in the differential diagnosis of high and low grade BSG, and Youden index was calculated to obtain the optimal diagnostic threshold. Pearson′s correlation coefficient analysis was used to evaluate the correlation between APTw signal intensity and Ki-67 expression.Results:There was no significant difference in age and gender distribution between high-grade and low-grade BSG patients. The maximum diameter of high-grade BSG was significantly larger than that of low-grade BSG [(4.7±0.9) vs. (3.1±1.7)cm; t=-2.94, P=0.007]; the maximum signal intensity of APTw (APTw max) in high-grade BSG was significantly higher than that in low-grade BSG [(4.9±0.6)% vs. (3.0±1.2)%; t=-5.14, P<0.001]; the average signal intensity of APTw (APTw mean) in high-grade BSG was significantly higher than that in low-grade BSG[(3.6±0.4%) vs. (2.7±1.1)%; t=-2.66, P=0.014].The area under the curve(AUC)of APTw max in distinguishing high-and low-grade BSG was 0.897; with 4.07% as the optimal diagnostic threshold of APTw max, the sensitivity for the diagnosis of high-grade BSG was 0.917 and specificity was 0.846. The AUC of APTw mean in distinguishing high-and low-grade BSG was 0.769; with 2.85% as the optimal diagnostic threshold of APTw mean, the sensitivity for the diagnosis of high-grade BSG was 0.917 and specificity was 0.692. There was a positive correlation between the value of APTw max and Ki-67 expression( r=0.453, P=0.023). Conclusion:APTw imaging is helpful to distinguish high-grade and low-grade BSG in children. APTw max value can be used to effectively evaluate the proliferative activity of BSG in children.