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 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 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.

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 To assess the value and feasibility of 64-slice spiral CT in diagnosis of coronary artery aneurysm in the follow-up of young children with previous Kawasaki disease. Methods Twelve boys (mean age 5.1 years) for follow-up (ranged 1.1 to 5.1 years) with known Kawasaki disease and coronary artery aneurysms underwent coronary CT angiography using 64-slice spiral CT.The number,location,shape and size of each coronary artery aneurysm were recorded and compared with those of echocardiography performed simutaneously. Results A total of 30 coronary artery aneurysms were identified with mean diameter of(7.5±3.8) mm,and mean maximum length of (12.4±9.1) mm.10 aneurysms were small in size,7 aneurysms were medium in size and 13 were giant aneurysms.Fourteen aneurysms were saccular,and the remaining 16 were fusiform. Among the aneurysms in left coronary artery,7 of them were located in the main branch,9 were located in the proximal segment of the anterior descending branch,4 were located at the middle segment of the anterior descending branch,and 2 were located in the circumflex branch.Among the aneurysms in right coronary artery,6 of them were located in the proximal segment,9 were located in the middle segment,and 4 were located at the distal segment.Nine of the aneurysms involved 2 segments of the coronary arteries,and one involved 3 segments.Six stenotic segments were found. Calcification was found in 5 aneurysms and 3 of them had thrombosis. Echocardiography failed to detect 8 aneurysms of small size and located in the middle or distal segments of the coronary arterys.Conclusion The 64-slice CT angiography proved valuable for monitoring young children with Kawasakidisease.

Objective To investigate the characteristics of spinal MR images in acute flaccid paralysis(AFP) associated with enterevirus 71 infected hand-foot-mouth disease.Methods The spinal MR images of eight infants with AFP and positive EV71 cultures were analyzed during an outbreak of hand-foot-mouth disease in China in 2008.Results Acute paralysis was observed in one lower limb in 4 of the 8 patients,in four limbs in 2 patients,in one upper limb and both lower limbs in 1 patient,2 of the 8 patients also had brain stem encephalitis.Lesions were identified in anterior horn regions of spinal cord with hyperintensity on T2-weighted images and hypointensity on T1-weighted images.Location of the lesions included C3 to C7(1 case),T10 extending to conus medullaris(5 cases)and a combination of the above (2 cases).Five of the 8 patients presented with unilateral paralysis.Two of the 5 cases showed unilateral hyperintense lesions in anterior horn regions and the remaining 3 cases showed bilateral hyperintense lesions in anterior horn regions with a unilateral predominance.One of the 3 patients with bilateral lesions showed slight enhancement of anterior horn with prominent enhancement of ventral roots after intravenous injections of contrast medium.Three of the 8 patients with bilateral paralysis showed bilateral hyperintensity in both anterior horn regions.Conclusion MR is the imaging medality of choice for the detection of radiculomyelitis of AFP associated with EV71 infection.

Objective To assess the feasibility of using an automatic tube current modulation (ATCM)method to obtmn consistent image quality with reduced radiation dose for young children undergoing chest scans with a set of 64-slice spiral CT.Methods Fifry young children underwent chest scans on a GE 64-slice VCT with automatic tube current modulation.The noise index(NI)for this study group was set to 8 or 9 based on the proposed reference for pediatric chest imaging in our hospital.We compared image quality and radiation dose for the study group with the age-matched control group of 50 young children acquired with standard protocol of fixed-mAs(120 and 150 mAs for under 1 and above 1 year old,respectively).The volume CT dose index(CTDIvol)values were recorded for beth groups.Two experienced pediatric radiologists assessed image quality on a 5-point scale with 5 being the best.Scores greater than or equal to 3 were considered clinically acceptable.The degree of interobserver concordance was determined by Kappa statistics.Results The average objective image noise and CTDIvol for control group was(4.78±0.58)and(6.68±0.62)mGy,respectively.For the study group the mean value of objective mAs wag(41.6±11.6)(20-79 mAs)with mean CTDIvol of(2.34 4±0.71)mGy,and the use of ATCM produced mean noise of(7.84±0.66).The average CTDIvol with the use of NI of 8-9 was about 65% lower than that with the fixed mAs setting.The mean image quality score for the study group and control group was(3.46±0.40)and(4.65±0.46)respectively.All studies had acceptable image quality,and there was good inter-observer agreement in diagnostic acceptability(Kappa=0.474 and 0.536).Conclusion The automatic tube current modulation method could be used to obtain consistent image qualityfor young children undergoing 64-slice MSCT chest scans.With proper noise level setting(NI=8 or 9),one may obtmn clinically acceptable images with much reduced radiation dose.

Objective To assess the clinical value of MSCT in congenital esophageal atresia (EA) and tracheoesophageal fistula (TEF) of newborns. Methods Twenty neonates (17 boys and 3 girls) with a mean age of 4.6 days (1 day to 16 days) diagnosed EA and distal TEF underwent MSCT, and multiple planar volume reconstruction (MPVR) and three-dimensional transparency lung volume rendering (TL-VR) imaging were used. The initial diagnosis was made on esophagram by showing the catheter into a blind-ended esophageal pouch. The MSCT manifestations were compared with the surgical findings. Statistical analysis was performed by using SPSS 10.0. Paired-Samples t test and Pearson correlation analysis were used. Results MSCT clearly showed the distal esophageal pouches in all EA patients. The distance between the proximal and distal esophageal pouches determined by MPVR (0.15--3.10 cm, median 0.70 cm) and TL-VR (0.10--3.10 cm, median 0.82 cm) had no remarkable differences and correlated well with the surgical findings (r=0.87, P<0.01). MPVR revealed the orifice of the fistula in 13 TEF cases, while TL-VR only in 4. Conclusion MSCT is an useful and noninvasive imaging method for demonstrating congenital EA and distal TEF, and is highly valuable for surgical planning.

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.

Objective To explore the difference between interval storage and continuous storage of dynamic imagines in contrast enhanced ultrasound (CEUS) quantitative analysis. Methods Two CEUS were performed for each of fifteen participants using interval storage and continuous storage of dynamic images. A number of parameters were analyzed including rising time (RT), time to peak (TTP), mean transit time (MTT), maximum intensity (IMAX), and area under the curve (AUC). The disk usage and time consumpation were also compared for analysis. Results There were no differences in RT, TTP, MTT, IMAX, AUC between the two groups (t=1.028, 1.012, 0.558, 0.223, 0.556, P=0.322, 0.329, 0.586, 0.826, 0.587). There was significantly positive correlations between them (r=0.989, 0.992, 0.867, 0.865, 0.947, all P<0.05). The disk usage in interval storage group was about 1/3 of that in contiunous storage group. And the interval storage method could saved 25-30 min in each case. Conclusion Interval storage is worthy for further clinical application on the groud of its disk usage sparing and less time consumpation without compromising the image quality for analysis.