Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.

Objective To evaluate the role of multi-slice computed tomography (MSCT) in the diagnosis of pulmonary sequestration.Methods MSCT scans of 18 cases of pulmonary sequestration proved by surgery and pathology were reviewed.All cases underwent plain and contrast enhanced CT scanning,and retrospective reconstruction was made.Various reconstruction techniques in displaying the pulmonary sequestration and associated malformation were evaluated.Results Anomalous systemic arterial supply was discovered by transverse CT images in 12 cases.The reconstructed images using multiple methods showed the aberrant artery more clearly in all cases,including 6 cases in which the abnormalities were not confirmed by transverse CT.Drainage vein was revealed in 13 cases and lung heteroplasia with other malformation was demonstrated in 14 cases.Volume rendering (VR) reconstruction is the optimal choice for displaying the abnormal vessels and airway.Conclusion Enhanced MSCT with image post-processing can show the abnormal artery and vein of the pulmonary sequestration and the associated malformation,so it is the first choice in diagnosing pulmonary sequestration in pediatric population.

Objective To study the application CT scans in Nuss procedure for pectus excavatum. Metlhods 648 children with pectus excavatum underwent Nuss procedure from July 2002 to September 2008 The preoperative CT scan was carried out for evaluation of the deformity degree and morphology classification of chest wall malformation, the deformity in relation with adjacent tissue and associated different disorder. Results Nuss procedure was successfully performed in all 648 patients. The preoperative CT scan showed medium deformity of the pectus excavatum in 73 cases ( 11.27% ) and severe deformity in 575 cases (88.73%). Morphologic classification of the pectus excavatum were symmetric type in 407cases (62.81% ) , eccentric type in 83( 12.81% ) ,and unbalanced type in 158( 24.38% ). 116 cases with pectus excavatum were associated with other different disorders, among them 55 cases ( 17.9% )were diagnosed by CT scan. 28 cases received stimultanously operation for their abnormalities. Conclusion CT scan is a useful tool for evaluation the deformity degree and morphology classification, direct the operation, reduce the complications and find other different disorders. It should be a routine examination before Nuss procedure.

Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; Genes, MHC Class I ; genetics ; HL-60 Cells ; Humans ; K562 Cells ; Killer Cells, Natural ; drug effects ; Leukemia ; genetics ; metabolism ; Polysaccharides ; pharmacology

Objective To explore the imaging features on chest radiograph and CT in children with Influenza A H1N1 pneumonia. Methods The imaging data of chest radiograph and CT in six children with Influenza A H1N1 pneumonia confirmed by real-time RT-PCR assay was retrospectively analysis. All patients had chest radiograph at first examination and 4 of them re-examed. One children took CT. Results All cases showed thick lung markings with varied degrees of pulmonary infiltration and interstitial changes on chest radiograph. Among them, 3 cases showed bilateral pulmonary infiltration and 3 cases showed infiltration in left lung; enlarged hilar was observed in 3 cases. The imaging findings of the pneumonia changed quickly during the follow-up accompanied with the improvement of clinical symptoms. The only one chest CT examination showed bilateral infiltration, multiple ground-glass opacities,small subpleural nodulars, right pleural effusion and lymphadenopathy of lung hila and mediastinum. Conclusions Chest radiograph and CT revealed certain typical imaging features in the children with influenza A H1N1 pneumonia. However, the final diagnosis of influenza A H1N1 pneumonia still should be made based on epidemiology and laboratory examination.

BACKGROUND:Alendronate is a new generation of diphosphate,which is the second generation of osteoporosis drugs.It is widely used to treat diseases related to increase of bone absorption in clinic.OBJECTIVE:To observe the effect of alendronate on the proliferation and the mRNA expression of osteoprotegerin(OPG) and receptor activator of nuclear factor kappa B ligand(RANKL) of human osteoblasts.DESIGN,TIME AND SETTING:A single sample observational experiment was performed at the Basic Research Institute of Chongqing Medical University from November 2007 to March 2008.MATERIALS:Osteoblasts were isolated from cancellous bone in a surgical operation.Alendronate was the product of Merck Sharp & Dohme S.p.A.METHODS:Osteoblasts were cultured with various concentrations of alendronate(1?10-9,1?10-8,1?10-7,1?10-6,1?10-5,1?10-4 mol/L).Osteoblasts cultured without alendronate were assigned as controls.MAIN OUTC0ME MEASURES:①The morphology and growth of osteoblasts were observed.②Effect of alendronate on the proliferation of osteoblasts were detected by MMT method.③The effect of various concentrations of alendronate on the mRNA expression of OPG and RANKL were detected by using RT-PCR.RESULTS:1?10-5 and 1?10-4 mol/L alendronate inhibited the proliferation of osteoblasts.1?10-9-1?10-6 mol/L alendronate promoted the proliferation of osteoblasts,and the 1?10-8 mol/L alendronate had the strongest effect.Alendronate inhibited RANKL mRNA expression in a concentration-dependent manner,1?10-5 mol/L alendronate had a strongest effect at 72 hours after culture(P

Objective To study the value of chest radiograph and thin-section computed tomography (CT) in diagnosis bronchiolitis obliterans in children, and to determine clinical view of obliterative bronchilitis in children. Methods We identified 12 infants, 10 boys, and 2 girls (age range, 5 month to 11 years) with clinical confirmation of bronchiolitis obliterans. Three cases were after Steven-Johnson syndrome, 8 were post-infection(2 adenovirus, 2 measles and 1 Pseudomonas aeruginosa infection, 3 cases were unknown etiology infection) ; The symptoms lasted for at least 6 weeks. One case had lung ventilation nuclear scan. We evaluated individual bronchscopy, pulmonary function test, chest radiograph and thin-section CT features and their characteristic appearance. Results All cases had typical clinical characteristics and pulmonary function testing results that were consistent with nonreversible small airways obstruction. One case had lung ventilation nuclear scan illustrated absent and reduced ventilation of the right lower lobe. Nine cases who underwent bronchoscopy were chronic endobronchial inflammation. Three children had transbronchial biopsy and 1 patient who underwent open pulmonary biopsies were uncertain of histological diagnosis. Chest radiography showed hyperinflation in 8 cases; peribronchial thickening in 6 cases; consolidation/atelectasia in 6 cases; unilateral hyperlucency of a small/normal-sized lung in 4 cases. Thin-section CT/HRCT features included: mosaic perfusion pattern, decreased lung attenuation in 11 cases, pulmonary vascular attenuation in 10 cases; bronchial dilatation in 7 cases; bronchial wall thickening in 9 cases; unilateral hyperlucency of a small/normal-sized lung in 5 cases; consolidation in 6 cases; nodular in 3 cases; mucoid impaction in 5 cases. Conclusions In our study, correct diagnoses of bronchiolitis obliterans in children were made more special with thin-section CT than with chest radiographs. The diagnosis of BO in children can be based on the characteristic clinical situation, pulmonary function, indicating minimally reversible airways obstruction and characteristic thin-section CT findings.

Objective Base on the local pathology, the early diagnosis and a reasonable treatment for congenital esophageal stenosis (CES) were discussed. Methods Forty two cases of congenital esophageal stenosis during 1980～2000 were reviewed retrospectively, including age, vomitus and frequency, nutrition and development, diagnostic method used and operative pathological findings, time of normal feeding and time of nutritional restoration. Results According to local pathology, there were 26 cases of tracheobronchial remnant, 11 fibromuscular stenosis, 3 membranous diaphragm, and 2 ectopic gastric mucosa. Membranous diaphragm excision gave the best result without postoperative dilatation. The patients were followed up for 4～10 years, Normal feeding was restored in 1 month in 78 6%, 9 5% in 6 months, and 11 9% in 1 year. Conclusion Persistent vomiting of undigested food and failure in gaining weight are the chief complaints of congenital esophageal stenosis. The confirmatory diagnosis depends on barium swallowing and esophagoscopy. A good result can be achieved by follows local resection and necessary postoperative dilatation.

Objective To access the development of thoracic volume of pectus excavatum use of Nuss operation used CT-basedpulmonary volumetric evaluation.Methods 98 patients with pectus excavatum in Beijing Children's Hospital under Nuss operation were documented.All patients had CT scan pre-and postopration.The CT-scan's data were calculated as lung's volume by handdraw-layers summation method.The lung's volume result was compared,and enquiry the position in CT lung volume developmental scale.Results The lung's volume was elevated 28.3％ after operation.The development of thoracic volume was keep with age,70％ was maintained and 15％ was elevated.Conclusion Nuss operation can prevent the decrease of thoracic volume in pectus excavatum.

Objective To observe the difference between skeletal age of hand and wrist and chronological age and explore the reliability of CHN radiographic atlas method to assess the skeletal age of hand and wrist in children and adolescent.Methods Total 1397 healthy children (666 boys,731 girls;age range,1.0-18.0 years old) with hand and wrist injury from 2007 to 2011 were selected.Forty groups (n =20 for boys and girls,respectively) were classified according to CHN radiographic atlas method.The radiographs of hand and wrist were assessed by CHN radiographic atlas method,the relations between skeletal age and chronological age were investigated by using Wilcoxon signed ranks test.Results According to the CHN radiographic atlas method,the difference in 1.0 to 3.9 years old,7.0 to 7.9 years old and 9.0 to 15.9 years old boy groups between skeletal age and the chronological age had statistical significance (P ＜0.05) ; the difference in 1.0 to 2.9 years old,8.0 to 11.9 years old,12.6 to 14.9 years old,and 17.0 to 18.0 years old girl groups between skeletal age and the chronological age had statistical significance (P ＜ 0.05).Besides,these skeletal age was higher than the chronological age.Conclusions Skeletal age assessed by the CHN radiographic atlas method in a majority of age groups was higher than chronological age.It should be cautious to estimate the contemporary Chinese children skeletal age of hand and wrist when using the CHN radiographic atlas method.