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The magnetization loss in a perpendicular external magnetic field is main AC loss of YBCO coated conductor for AC power applications. One of solutions for decreasing the magnetization loss is to make striations on it and to transpose the striated coated conductors. We measured the magnetization losses of several samples made by striated and transposed YBCO coated conductors in external magnetic field with an inclined angle for wide face of YBCO coated conductor. We compared the measured magnetization loss at an arbitrary direction in the magnetic field with those measured in a perpendicular magnetic field at the same value of perpendicular component of the external magnetic field. The results agree well with each other in all samples. This means that the magnetization loss in any directional applied magnetic field can be estimated by using only the perpendicular loss data.

To evaluate whether perfusion magnetic resonance (MR) imaging can depict hemodynamic status after revascularization surgery and whether changes at perfusion MR imaging after revascularization surgery correspond with clinical outcome in moyamoya disease.An institutional review board approved this retrospective study; informed consent was waived. Pre- and postoperative perfusion MR imaging data in 67 children with moyamoya disease (mean age, 7.2 years; range, 2-13 years) were included. Regional time to peak (rTTP) and regional cerebral blood volume (rCBV) were calculated by adjusting cerebral time to peak (TTP) and cerebral blood volume (CBV) values by using cerebellar reference values. For quantitative regional analysis, pixel values were divided into five categories (0,2,4,6, and8 seconds), and percentages of pixels in rTTP meeting these time conditions were calculated. Changes in the values after revascularization were calculated. Postoperative clinical outcomes were categorized as follows: 1 indicated excellent; 2, good; 3, fair; and 4, poor. Pre- and postoperative perfusion parameters were compared by using a paired t test; relationships between perfusion parameters and clinical outcomes were investigated by using one-way analysis of variance, with a significance level of .05.rTTP, rCBV, and percentage of pixels of rTTP decreased significantly after revascularization surgery. Pre- and postoperative rTTP were significantly different for the clinical outcome categories. Change in rTTP and change in percentage of pixels of rTTP (0 seconds to6 seconds) were significantly different for the clinical outcome categories.TTP and CBV perfusion maps can depict hemodynamic status after revascularization surgery in moyamoya disease. Furthermore, changes in TTP perfusion maps after revascularization surgery correspond with clinical outcome in patients with moyamoya disease.

The objective of this study is to present the two-step dispatching strategy for the purpose of the transport vehicle with multi-function used in container terminal. The two-step dispatching is a method to save the waiting time between transport vehicle and cranes using real time location control. The first step dispatching is to allocate the destination location based on the real time location information. The second step dispatching is to indicate the specific job such as loading, unloading, and pick-up based on the condition of working area. This two-step dispatching strategy decreases the waiting times of the stevedoring system and will contribute at a productivity improvement in container terminal.

The operation of the SMES system can be divided into three modes such as charging, operating and discharging. During the charging and the discharging modes, a magnetic field variation due to the current increase and decrease generate eddy current losses in the SMES system. The eddy current loss in discharging mode is the major factor to be considered because the operating time in the mode is fixed, whereas the charging mode has the arbitrary operating time which is not fixed. In this paper, we present the analysis results of the eddy current losses which are generated in the 600 kJ class HTS SMES system during the discharging mode.

Even though a coated conductor is more superior in some performances than a BSCCO PIT wire, its AC loss is still high. One of the solutions to decrease the AC loss of the coated conductor is to make striations on it and to twist it. But we cannot use the twisted single coated conductor for a winding of an AC machine. Instead of the twist, the transposed coated conductors which have striations on themselves can be used. To estimate the effect of magnetization loss reduction, several short samples having or not having striations and transposition are prepared. Each sample is tested in perpendicular external magnetic fields. Test results of several samples with a striation and transposition give the possibility on lower magnetization loss.

A small SMES system and a 600 kJ SMES model coil were fabricated. High temperature superconducting (HTS) wire which was reinforced with stainless steel was used for winding the model coil and its critical current was 624 A at self-field and 20 K. The type of model coil is double pancake coil (DPC). The number of turns of a DPC is 282 and length of HTS wire per DPC is about 220 m. A two stage GM cryo-cooler (RDK-408) was used for cool down the SMES system and mounted in the middle of the top plate of a cryostat which has 580 mm outer diameter. Cooling plates for conduction cooling were placed on top and bottom of DPC. Operating temperature of the system is 20 K. Cryogenic temperature sensors (Cernox, SD type) were attached on the surface of a copper cylinder block for cool down test of the system. Temperature control test by a heat load also carried out.

A 100 MVA, commercial class high temperature superconducting (HTS) transformer was designed. In this paper the cryogenic system to extract the heat generated at the winding due to the AC loss and the heat penetration through the wall and the current lead and keep the winding temperature under design temperature is presented. The operation temperature is set at 67 K to increase the critical current and reduce the amount of HTS tape usage and the volume. The HTS winding was concentrically arranged to reduce the AC loss. The system consists of main cryostat with the windings and secondary cryostat with cooler, cryopump and the heat exchanger inside. The liquid nitrogen is entering the main cryostat at 65 K and assumed to be leaving at 67 K. The winding temperature distribution is simulated with the anticipated heat load using Fluent. The effect of the liquid nitrogen flow rate, inlet location is investigated and discussed.

HTS transformers which have been developed until now had only fundamental structures. Among the auxiliary functions of conventional transformers, voltage regulating is the most important one. For the voltage regulation, conventional transformers are equipped with on load tap changers (OLTCs). In this paper, we investigate the possibility of the HTS transformer with OLTC. For the case study, we designed a single phase 33 MVA HTS transformer with OLTC. It is one of three individual HTS transformers which composes a 3 phase, 100 MVA transformer. It is expected to substitute for a 3 phase, 60 MVA conventional transformer in Korea. The parameters of an HTS transformer are varied due to the gap length between primary and secondary windings. The length was decided for the transformer to have the impedance of 12%. Its size was limited to the one of the conventional transformer. The characteristics of the HTS transformer were analysed in both case of having OLTC and not.

Because of the shape of the HTS tapes, the layer winding is not good for high voltage power transformer. The double pancake winding which is one of disk windings is good for the insulation and limitation of voltage stress, but it makes high AC losses. So we have proposed a new winding method which is called continuous disk winding (CDW) for high voltage HTS transformers and has advantages from both layer and double pancake windings. In this paper, we calculated numerically and measured AC losses in the HTS continuous disk winding. 4 kinds of short samples with different numbers of stacked HTS tapes were made and their AC losses were measured. These data were used in the process of calculation, making the result more precisely. Other properties such as the critical current, inductance and capacitance were analysed numerically and tested also.

According to the recent design of an HTS (high temperature superconducting) power application whose capacity is hundreds MVA, the rated current is over thousand amps. Considering the performance of the recent HTS tapes, it is inevitable to use several HTS tapes in parallel for high capacity current. In this paper, we have investigated the influence of current distribution on the AC loss in the multi-stacked superconducting wire. The dependence of AC loss and critical current on the current distribution in multi-stacked wires was discussed. We fabricated multi-stacked wires and measured the current distribution at 77 K. The current distribution was indirectly found from the self-field distribution. The magnetic field was measured by an array of hall sensors located around the HTS superconducting wires. In the case of non-uniform distribution of current, the performance of multi- stacked HTS wires is worse than that of uniform current distribution.

To evaluate sonographic findings in ischemic enterocolitis (IEC) and correlate with pathologic findings in an experimental study.Ischemic enterocolitis was induced with ligation of the superior mesenteric artery in 20 rabbits. Plain radiography and ultrasonography (US) were performed. US was done hourly after the ligation using 10 MHz linear probe. US findings were categorized into 2 groups according to the bowel wall echogenicity; the echogenic dots (ED) group and the circumferential granular echogenicity (CGE) group. US findings were compared with the specimen radiography and the histopathology.On US, ED were seen in the bowel of all rabbits after SMA ligation (2.2 +/- 1.3 hours [standard deviation]) and CGE in 16 rabbits (4.1 +/- 0.9 hours). On the specimen radiographs, multiple radiolucent air bubbles were present. Comparing the ED and CGE group, histopathological findings revealed the CGE group had severer injury of the bowel wall than the ED group. On plain radiography, there was progressive bowel distention, but pneumatosis intestinalis (PI) was not evident.ED or CGE are the sonographic findings of ischemic enterocolitis, and bowel wall echogenicity might reflect the degree of ischemic injury.

Widespread use of fetal ultrasonography is accompanied by more frequent detection of antenatal hydronephrosis. Therefore, sonographic evaluation of neonates with a history of antenatal hydronephrosis is becoming more widespread. As an initial postnatal non-invasive imaging modality, ultrasonography is used to screen for persistence of hydronephrosis, determine the level and severity of obstruction, and contribute to appropriate diagnosis and treatment. This review aims to provide a practical overview of the sonographic evaluation of neonatal hydronephrosis and to describe the sonographic findings of conditions associated with hydronephrosis in the newborn.

Crohn's disease is a chronic idiopathic inflammatory disease of the intestines characterized by frequent relapse and remission. It often develops in children and adolescents, who are vulnerable to repeated exposure to ionizing radiations. Magnetic resonance enterography (MRE) is an increasingly important radiation-free imaging modality that is used to evaluate pediatric patients with Crohn's disease. MRE can evaluate extraluminal and extraintestinal abnormalities as well as the status of the bowel wall. In addition, MRE has an advantage in the evaluation of the small bowel involvement. MRE can be used for the initial diagnosis of Crohn's disease, and can aid in the assessment of disease activity and complications such as penetrating and fibrostenotic diseases. The aims of this article are to review the MRE technique for obtaining diagnostic and high-quality images and to discuss interpretations of imaging findings in patients with Crohn's disease.

CT of pediatric phantoms can provide useful guidance to the optimization of knowledge-based iterative reconstruction CT.To compare radiation dose and image quality of CT images obtained at different radiation doses reconstructed with knowledge-based iterative reconstruction, hybrid iterative reconstruction and filtered back-projection.We scanned a 5-year anthropomorphic phantom at seven levels of radiation. We then reconstructed CT data with knowledge-based iterative reconstruction (iterative model reconstruction [IMR] levels 1, 2 and 3; Philips Healthcare, Andover, MA), hybrid iterative reconstruction (iDose(4), levels 3 and 7; Philips Healthcare, Andover, MA) and filtered back-projection. The noise, signal-to-noise ratio and contrast-to-noise ratio were calculated. We evaluated low-contrast resolutions and detectability by low-contrast targets and subjective and objective spatial resolutions by the line pairs and wire.With radiation at 100 peak kVp and 100 mAs (3.64 mSv), the relative doses ranged from 5% (0.19 mSv) to 150% (5.46 mSv). Lower noise and higher signal-to-noise, contrast-to-noise and objective spatial resolution were generally achieved in ascending order of filtered back-projection, iDose(4) levels 3 and 7, and IMR levels 1, 2 and 3, at all radiation dose levels. Compared with filtered back-projection at 100% dose, similar noise levels were obtained on IMR level 2 images at 24% dose and iDose(4) level 3 images at 50% dose, respectively. Regarding low-contrast resolution, low-contrast detectability and objective spatial resolution, IMR level 2 images at 24% dose showed comparable image quality with filtered back-projection at 100% dose. Subjective spatial resolution was not greatly affected by reconstruction algorithm.Reduced-dose IMR obtained at 0.92 mSv (24%) showed similar image quality to routine-dose filtered back-projection obtained at 3.64 mSv (100%), and half-dose iDose(4) obtained at 1.81 mSv.

To compare image quality and radiation dose between high-pitch mode (HPM) and low-pitch mode (LPM) CT in young children. Forty-seven children (mean age 35.6 months; range, 0–126 months) underwent 49 CT examinations in HPM or LPM and were divided into high or low respiratory rate (RR) groups. A qualitative image quality was compared between the two modes. The volume CT dose index (CTDIvol) and dose-length product (DLP) were evaluated from the dose reports, and effective doses were assessed using a paediatric phantom. Image quality was generally better for HPM than LPM (diagnostic acceptance score, 4.00 vs. 3.46, P = 0.004); the difference was more prominent in the high RR group (4.00 vs. 3.22, P = 0.001). However, there was no significant difference in the low RR group. The mean DLP value was higher in HPM than LPM (29.48 mGy · cm vs. 23.46 mGy · cm, P = 0.022), while CTDIvol was not significantly different. The total effective radiation dose was 26 % higher in HPM than LPM (1.82 mSv vs. 1.44 mSv). LPM can be considered for paediatric lung evaluation in young children with low RRs to reduce radiation dose while maintaining favourable image quality. • Radiation exposure is higher on high-pitch “Flash spiral mode” than on low-pitch “X-CARE mode”. • “Flash spiral mode” generally showed better image quality than “X-CARE mode”. • Difference in image quality was more prominent in the high RR group. • There was no difference in image quality in the low RR group. • “X-CARE mode” should be considered in a limited population with low RRs.

Objective To assess the diagnostic value of various ultrasound (US) findings and to make a decision-tree model for US diagnosis of biliary atresia (BA). Materials and Methods From March 2008 to January 2014, the following US findings were retrospectively evaluated in 100 infants with cholestatic jaundice (BA, n = 46; non-BA, n = 54): length and morphology of the gallbladder, triangular cord thickness, hepatic artery and portal vein diameters, and visualization of the common bile duct. Logistic regression analyses were performed to determine the features that would be useful in predicting BA. Conditional inference tree analysis was used to generate a decision-making tree for classifying patients into the BA or non-BA groups. Results Multivariate logistic regression analysis showed that abnormal gallbladder morphology and greater triangular cord thickness were significant predictors of BA (p = 0.003 and 0.001; adjusted odds ratio: 345.6 and 65.6, respectively). In the decision-making tree using conditional inference tree analysis, gallbladder morphology and triangular cord thickness (optimal cutoff value of triangular cord thickness, 3.4 mm) were also selected as significant discriminators for differential diagnosis of BA, and gallbladder morphology was the first discriminator. The diagnostic performance of the decision-making tree was excellent, with sensitivity of 100% (46/46), specificity of 94.4% (51/54), and overall accuracy of 97% (97/100). Conclusion Abnormal gallbladder morphology and greater triangular cord thickness (> 3.4 mm) were the most useful predictors of BA on US. We suggest that the gallbladder morphology should be evaluated first and that triangular cord thickness should be evaluated subsequently in cases with normal gallbladder morphology.

The objective of this study is to develop the alternative model of the container transport vehicle of high productivity for the purpose of the increase of terminal productivity. In order to develop the alternatives, we analyze the technical specification of existing transport vehicles such as YT(Yard Tractor), S/C(Straddle Carrier), SHC(Shuttle Carrier), and AGV(Automated Guided Vehicle) and investigate the operation and performance of transport vehicles to classify the technical generation. The development alternative of transport vehicle presented in this study will usefully be apply to advanced container terminal with higher productivity in near future.

OBJECTIVE. As complications of tuberculosis are frequent in infancy, correct diagnosis of tuberculosis in infants is important. The purposes of this study are to summarize radiographic and CT findings of pulmonary tuberculosis in infants and to determine the radiologic features frequently seen in infants with this disease.CONCLUSION. Frequent radiologic findings of pulmonary tuberculosis in infants are mediastinal or hilar lymphadenopathy with central necrosis and air-space consolidations, especially masslike consolidations with low-attenuation areas or cavities within the consolidation. Disseminated pulmonary nodules and airway complications are also frequently detected in this age group. CT is a useful diagnostic technique in infants with tuberculosis because it can show parenchymal lesions and tuberculous lymphadenopathy better than chest radiography. CT scans can also be helpful when chest radiographs are inconclusive or complications of tuberculosis are suspected.

Port development has been remarkably increasing due to the progress of industrialization in ASEAN area. Especially, Vietnam has increased the international physical distribution in this area rapidly. The main issues facing decision makers at container terminals in Vietnam are how to expand the existing container terminals and construct new container terminals. In this paper, we performed the basic design based on simulation analysis in order to support the expansion of Quy Nhon port in Vietnam as a case study. The preliminary capacity analysis was conducted on the one berth at the port to analyze the scale of C/C(Container Crane)and yard area. Alternative scenarios were created based on the preliminary capacity analysis and the detailed simulation analysis was conducted for supporting the scenarios.

Larsen syndrome is characterized by multiple congenital joint dislocations and a characteristic flattened facial appearance. The aetiology is unknown, but the syndrome is considered a probable connective tissue disorder and the cardiovascular manifestations are similar to those of Marfan syndrome. We describe an 8-year-old girl with the characteristic features of Larsen syndrome who was also affected by a saccular aneurysm of the descending aorta, just distal to the left subclavian artery. We present the radiological findings and review the literature.

Background: Nutcracker syndrome is characterized by gross haematuria caused by left renal vein (LRV) entrapment. Objective: To assess the role of LRV ultrasonography in the diagnosis of the nutcracker syndrome in children. Materials and methods: Twelve children (eight male, four female; mean age 12.8 years) with venographically confirmed nutcracker syndrome (LRV-IVC pressure gradient ≥3 mm Hg) underwent LRV sonography including Doppler spectral analysis (n=7). The diameter and peak velocity (PV) were measured at two sites of the LRV (renal hilum and aortomesenteric portion). The US findings of nutcracker syndrome were compared with those of 20 control subjects using the t-test. We identified the optimal cut-off value of the US parameters for the diagnosis of the nutcracker syndrome using ROC analysis. Results: The PV at the aortomesenteric portion and the ratio of the PV between the two measured points showed significant differences between the two groups (P

Background. Adenoid cystic carcinoma (ACC) of the Bartholin's gland is a rare malignancy of the female genital tract and there have been 62 cases of ACC of the Bartholin's gland in the literature. Cases. Two cases of ACC of the Bartholin's gland are reported. Conclusion. There is no consensus on optimal treatment of ACC of the Bartholin's gland. Most commonly, wide local excision and radical vulvectomy with or without lymph node dissection, are performed. More long-term follow up is recommended to evaluate optimal primary treatment and roles of radiotherapy and chemotherapy because ACC of the Bartholin's gland recurs and metastasizes long after primary treatment.

Background: The diagnosis of squalene aspiration pneumonia in children is often difficult because of minimal non-specific symptoms. Objective: To investigate the radiological findings of squalene aspiration pneumonia in children. Materials and methods: We reviewed the chest radiographs (n = 8) and CT scans (n = 7), including high-resolution CT (n = 3), of eight patients (four boys, four girls; age 3 months to 6 years) with squalene aspiration pneumonia. All patients presented minimal symptoms. Results: Chest radiographs showed right-sided predominantly parahilar infiltrations. The extent and the opacity of the lesions decreased slowly during the follow-up period (mean 5.4 months) after halting the exposure. On CT, affected areas appeared as dense consolidations surrounded by ground-glass opacities showing a crazy-paving pattern in a geographic lobular distribution in all patients. The lesions were predominantly in the right lung and dependent areas in all patients and extensively involved all pulmonary lobes in five patients. Conclusions: These radiological findings, although non-specific, can lead to an appropriate diagnosis, particularly when patients present few symptoms.

This study was performed to analyze the operation system of transfer crane to improve the reality of yard operation rules in container terminal and present the applicable method of operation rules to apply the operation priority. And we derived the procedure to estimate the maximum number of waiting truck based on the waiting of truck and the occupancy of driving lane in yard, and analyzed the constraint state of space. To solve the space constraint, we provided a multi-job principle to define the space resource and described the solution and sequence diagram for the principle.

Subependymomas are rare, slow-growing, benign intraventricular tumors which occur commonly in the fourth or lateral ventricle. They usually occur in elderly men and often are asymptomatic and discovered incidentally. We report a case of a 6-year-old girl with a symptomatic subependymoma in the third ventricle with MR imaging.

The purpose of this study is to estimate the required number of yard tractor on port container terminal. The number of yard tractor is the bottleneck factor on the efficiency of container terminal. Due to the change in travel speed and travel distance, the efficiency is difficult to estimate. The efficiency of yard tractor is estimated by the proposed simulation model that developed considering the queueing network between container crane and transfer crane. The number of yard tractor per container crane is estimated by the alternative analysis. And to determine the number of yard tractor per container crane, the performance measure such as the distance between berth and yard, the speed of yard tractor are simulated.

In high temperature superconducting (HTS) transformer with double pancake windings, the perpendicular component of leakage magnetic flux density (B/sub r/) applied to HTS tapes of double pancake windings is larger than that of solenoid windings, which acts as a cause to decrease the critical current in HTS tape and increase AC loss. In this paper, in order to reduce the B/sub r/ applied to HTS windings, the use of ferrite flux diverters is presented. Flux diverters are located in between the primary windings and the secondary windings, and must be made of low-loss materials to minimize the heat. And electromagnetic analysis of a single-phase 1 MVA 22.9 kV/6.6 kV HTS transformer with flux diverters in HTS windings was accomplished. The variation of B/sub r/ applied to the secondary windings and magnetic flux density in flux diverters were analyzed by changing their relative permeability of flux diverters respectively. Suitable relative permeability of flux diverters to reduce B/sub r/ applied to HTS windings was selected, considering flux diverter losses by increment of B in flux diverters.

A high-definition analysis based on flow topology is made on the vortex motions under natural and lock-on conditions in the near-wake region of a circular cylinder, where two-dimensional flow fields in the wake-transition regime are measured by a time-resolved PIV system. The Reynolds stress distributions are examined in view of the mean separation streamline and the trajectory of the vortex center. It is shown that, by the lock-on, the Reynolds stresses become stronger and their dispositions match well with the shortened wake bubble, indicating perfect synchronization of shedding to the oscillatory forcing flow in the near field, which causes increased lift and drag forces.

A basic concept of TAS(Tractor Appointment System), which not only enhances the terminal productivity, but also yields higher efficiency of domestic CT(Container Terminal), is developed in this paper for CT to more competitive and serviceable. To analyze the effects of TAS when applied to the existing four-tier CT, a quantitative analysis is performed. The results showed that the number of rehandling time of CT has been significantly decreased, the efficiency of CT increased, and the flow time of trucks in CT reduced in a great deal

To assess the usefulness of infracoccygeal transperineal ultrasonography (US) in differentiation between high- and low-type imperforate anus.Infracoccygeal US was prospectively performed with a 7-10-MHz linear-array transducer prior to corrective surgery in 14 neonates with imperforate anus. The approach site was just inferior to the coccyx and posterior to the anus. Transverse images of the anorectal area were obtained. The puborectalis muscle was identified, and the relationship between the puborectalis muscle and the distal rectal pouch was evaluated. US findings were compared with surgical findings.In 10 neonates, a low-type imperforate anus was correctly diagnosed at infracoccygeal US. In those with low-type imperforate anus, the puborectalis muscle was seen as a hypoechoic U-shaped band (n = 10), and the distal rectal pouch passed through the puborectalis muscle (n = 10). In four neonates with high-type imperforate anus, the puborectalis muscle was not identified (n = 4).Infracoccygeal transperineal US enables the determination of the type of imperforate anus.

Teratoid Wilms tumor is defined as an unusual variant of nephroblastoma, in which there is a significant diversity of cell types and tissues in a neoplasm, where areas of classic nephroblastoma tissue are also present. We report a case of teratoid Wilms tumor demonstrated as a unilateral cystic and solid renal mass containing fatty tissue on ultrasonography and computed tomography.

Inflammatory myofibroblastic tumour of the liver is a rare disease in children and is characterized by an inflammatory mass of uncertain aetiology which simulates a true neoplasm, often resulting in a diagnostic dilemma. We report a pathologically proven case of inflammatory myofibroblastic tumour of the liver in a 14-month-old boy with jaundice. CT and MRI showed an ill-defined, homogeneously enhancing mass located in the hilar portion of the liver with biliary obstruction. He underwent percutaneous transhepatic biliary drainage to relieve obstructive jaundice, followed by lobectomy and, finally, liver transplantation.

Gastric adenomyoma is a rare tumour-like lesion composed of glandular components and smooth muscle bundles. We report a case of gastric adenomyoma in a 1-week-old neonate who presented with gastric outlet obstruction. To the best of our knowledge, this is the youngest child reported with gastric adenomyoma and a unique case demonstrating radiological findings of gastric adenomyoma in a young infant. At US, the lesion was seen as an asymmetrical mass-like wall-thickening of the pylorus. Upper gastrointestinal series showed findings similar to those seen in a case of hypertrophic pyloric stenosis. We suggest that gastric adenomyoma should be included in the causes of gastric outlet obstruction in neonates even though it is rare in young children.

Metachronous multifocal osteosarcoma (MFOS) is a rare form of osteosarcoma manifested by one or more new tumors developing after the initial treatment of primary osteosarcoma. The pathogenesis of metachronous MFOS is still obscure whether it represents multiple true primaries or metastatic disease. However, there is a clinical significance that metachronous MFOS is a potentially curable disease [Resnick D, Kyriacos M, Greenway GD. Tumors and tumor-like lesions of bone: imaging and pathology of specific lesions. In: Resnick D, editor. Diagnosis of bone and joint disorders. Philadelphia: Saunders, 1995: p. 3697-9.]. To our knowledge, there have been only a few reports about metachronous MFOS. We report a case of MFOS in a 14-year-old boy with review of the literature.

Pulmonary alveolar proteinosis (PAP) is a rare disease in children characterized by intra-alveolar accumulation of surfactant proteins, which severely reduces gaseous exchange. Whole lung lavage (WLL) is the preferred technique for the treatment of severe PAP. Herein, we present a pediatric case of PAP treated with WLL. An 11-year-old boy was admitted with the chief complaint of a dry cough lasting 6 months. He developed symptoms of dyspnea on exertion and had difficulty in climbing stairs. He was ultimately diagnosed with PAP through video-assisted thoracoscopic lung biopsy. As first-line of treatment for PAP, he underwent therapeutic WLL for each of his lungs on separate days. After a brief recovery, his symptoms gradually worsened; therefore, he underwent a second WLL. This is the first pediatric case of PAP relapse despite successful WLL in Korea.

Hemodynamic changes in the distal arteries during transfemoral catheterization in children have not been documented. To evaluate arterial flow changes of the lower extremities ipsilateral to the puncture site using Doppler US during transfemoral cerebral angiography in children. Twenty-seven children who underwent transfemoral cerebral angiography at our institution between April 2013 and August 2013 compose our study population. Doppler US was performed to evaluate diameters and peak systolic velocities of the common femoral artery and superficial femoral artery before and after femoral sheath insertion. Children were classified into three groups based on the spectral waveform changes of the superficial femoral artery after femoral sheath insertion. Thereafter, one-way ANOVA followed by the Bonferroni post-hoc comparisons test were performed to compare values among the groups. Mean common femoral artery and superficial femoral artery baseline diameters were 4.10 mm and 3.32 mm, and mean baseline peak systolic velocities were 218.26 and 166.51 cm/s, respectively. Fourteen of 27 children showed persistent triphasic flow in the superficial femoral artery (group 1); 7 children showed altered flow of biphasic (n = 3) or monophasic (n = 4) waveforms (group 2); and 6 children showed pulsus tardus et parvus pattern (group 3) after femoral sheath insertion. Mean baseline diameter of the common femoral artery and mean subtracted value between common femoral artery and femoral sheath size were significantly smaller in group 3 than the other groups. Size discrepancy between common femoral artery and femoral sheath was

Herpes simplex virus (HSV) type I causes a fulminant necrotising meningoencephalitis distinguished from other encephalitides by its focal and often haemorrhagic nature. Specific antiviral therapy with acyclovir can significantly improve the prognosis. We present MRI findings of two cases of herpes simplex encephalitis (HSE) confirmed by PCR analysis, focusing on the serial changes after acyclovir therapy: gyral swelling, high signal intensity on T2-weighted images in the subfrontal region, temporal lobe and insula in the initial stage, then regional extension with enhancement and haemorrhage despite appropriate acyclovir therapy, and finally encephalomalacia and brain atrophy.

On occasion, outbreaks of infection with adenovirus types 3, 7, and 21 cause severe lower respiratory tract infections (LRTIs) in children. From 1990 to 1998, all cases of LRTI due to adenovirus at the Seoul National University Children's Hospital, Seoul, Korea, were reviewed. Adenoviruses were recovered from nasal aspirate specimens of 87 (5.9%) of 1472 children with LRTI. The principal adenovirus serotypes were type 2 (13 [15%] of 87 strains), type 3 (13 [15%]), and type 7 (36 [41%]). Of the 87 infections, 62 (71%) occurred in children

We present a case of intramedullary spinal gangliocytoma in a 7-year-old girl who presented with scoliosis and progressive weakness of both legs. The tumour involved the whole spinal cord and medulla oblongata and was composed of inner cystic and outer solid components. On MRI, the solid portion of the lesion showed strong enhancement at the thoracolumbar level and mild enhancement at the cervical and medullary levels. Histological examination of the surgical specimen showed neoplastic ganglion cells arranged irregularly in benign normocellular glial background, which made a diagnosis of gangliocytoma.

Posterior circulation infarction is uncommon in children. We describe the clinical presentation and radiological findings in two children with cerebellar infarction resulting from dissection of the vertebral artery. We emphasize that vertebral artery injury should be considered in a child with acute symptoms and signs of ischaemia in the posterior circulation. MRI and MRA may be helpful in the diagnosis of cerebellar infarction and vertebral artery abnormality.

The most important complication of skeletal injuries involving the growth plate is growth disturbance. The purpose of this study was to evaluate MR features of growth plate modification after fat graft interposition in growth plate injury and to correlate these findings with pathological findings.A growth plate injury model was used in 12 skeletally immature rabbits. A longitudinal drill hole 5 mm in diameter was created in the central part of the growth plate in the distal femur, bilaterally. One side was filled with autologous fat, and the contralateral defect was left empty as a control. Magnetic resonance imaging was obtained 1, 3, and 6 months after surgery, and routine histological study was performed. The authors evaluated sequential changes in MR images and the histological basis of MR findings.In grafted femur, the signal intensity of the grafted area was lower than that of the surrounding bone on T2-weighted images at 1 month. The growth plate defect at 3 to 6 months was modified and had a proximally tapering appearance. The ratio of the growth plate defect was smaller in the grafted femur than in the control femur after surgery. Histologically, the fat-grafted area was replaced by fibrous connective tissue. In the control femur, a bony bridge was rectangular in the longitudinal direction and showed isosignal intensity with a rim of low signal intensity on T1-weighted imaging. Histologically, the defect was filled with mature fatty marrow with new bone formation in the control femur.The proximally pointing appearance and the low signal intensity of the grafted area on MR suggested fibrous degeneration of grafted fat that prevented solid bony bridge formation in experimentally induced growth plate injury.

Most pediatric chest diseases are adequately evaluated with chest radiography. However, when chest radiography does not allow identification of the location and nature of an area of increased opacity, ultrasonography (US) can help establish the diagnosis. US may be helpful in evaluation of persistent or unusual areas of increased opacity in the peripheral lung, pleural abnormalities, and mediastinal widening; US is particularly useful in patients with complete opacification of a hemithorax at radiography. In cases of pulmonary parenchymal lesions, identification of air or fluid bronchograms at US and of pulmonary vessels at color flow imaging is useful for differentiating pulmonary consolidation or atelectasis from lung masses and pleural lesions. US allows characterization of pleural fluid collections as simple, complicated, or fibroadhesive, which is important information for planning thoracentesis or thoracotomy. Computed tomography and magnetic resonance imaging are superior to US in evaluation of the mediastinum, but US is a reasonable alternative in certain situations (eg, to avoid unnecessary investigation of a normal thymus simulating a mediastinal mass). In cases of chest wall lesions, US may enable localization of the site of origin to soft tissues or an extrapleural intrathoracic location. Osseous involvement, particularly rib involvement, is easily evaluated with US.

Background.The clinical course ofMycoplasma pneumonia is typically mild and self-limited. There are, however, several case reports of severe complication following this illness with considerable morbidity and mortality.Objectives.This study was conducted to investigate, using high-resolution computed tomography (HRCT), the long-term pulmonary structural abnormalities after Mycoplasma pneumonia and to identify risk factors (chest radiograph findings, antibody titers, and host factors) that might increase the likelihood of developing the sequelae.Methods.Thirty-eight children requiring hospitalization attributable to Mycoplasma pneumonia were recruited by the retrospective examination of hospital records. They underwent HRCT after an interval of 1.0 to 2.2 years. A control group of 17 children with the history of Mycoplasma upper respiratory infection was also studied after a similar interval.Results.Abnormal HRCT findings were present in 37% (14/38) of the pneumonia group, compared with 12% (2/17) of the control group. The abnormalities in the pneumonia group, which appeared alone or in combination, included mosaic perfusion (n =12), bronchiectasis (n = 8), bronchial wall thickening (n = 4), decreased vascularity (n = 1), and air trapping on expiratory scan (9 of 29 tested). The area affected by these abnormalities, usually involving 2 or more lobes, corresponded in all cases to the location of the infiltrate on chest radiograph at the time of pneumonia. Between subjects with abnormal HRCT (n = 14) and normal HRCT (n = 24) in the pneumonia group, significant differences were observed in age at the time of pneumonia (mean ± standard deviation: 5.3 ± 2.0 years vs 7.7 ± 3.4 years) and peak antimycoplasma antibody titer (geometric mean [range of 1 standard deviation]; 1:7943 [3126–19 953] vs 1:3093 [832–11 482]).Conclusions.We conclude that a considerable proportion of children with history of Mycoplasma pneumonia have abnormal findings on HRCT, suggestive of small airway obstruction and that younger age and higher antibody titer at the time of pneumonia may be risk factors for these sequelae.

To evaluate sequential changes in thin-section computed tomographic (CT) findings after inducement of lipoid pneumonia and provide the histopathologic bases of these findings.Shark liver oil was administered to 12 sites in seven pigs. Thin-section CT scans were obtained within 1 hour and at 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after oil administration. Scans were assessed for opacity, distribution, location at the lobular level, extent, and volume of the lesions. The CT number in consolidation areas also was measured. Findings at CT were correlated with those in the histopathologic specimens.Diffuse ground-glass opacity was noted on all immediately obtained scans. The opacity of the lesions was highest at 1 week; then it decreased gradually to an area of ground-glass opacity. The extent and volume of the lesions decreased at follow-up CT. Histopathologically, the lesions showed a lobular distribution sharply demarcated from the normal lungs. The lobules of decreased volume showed residual thickening of the alveolar walls with bronchiolectasis and mild collagen deposition of the interlobular septa. Pathologic examination of the low-attenuating consolidation area at CT revealed evidence of partial aeration.Thin-section CT findings of lipoid pneumonia include ground-glass opacity and airspace consolidation, followed by complete or incomplete resolution with volume loss and septal thickening. Low-attenuating consolidation at CT does not always indicate the presence of fat.

Depth profiling of a multilayered thin film (Ta2O5 (18 nm)/SiO2 (0.5 nm)) on Si and a 1 nm ultra-thin single layer (Ta2O5 (1 nm)/SiO2 (20 nm)) sample was studied by Secondary Ion Mass Spectrometry (SIMS) and Dynamic Monte Carlo simulation approach. This approach is based on the binary encounter model, taking into account (1) generation of both the interstitial atoms and vacancies and (2) annihilation of the vacancies. The observed 1–3 nm shift of the delta layer peak to the surface direction in SIMS depth profiling could be explained with Dynamic Monte Carlo simulation approach, which describes atomic mixing phenomena in depth profiling of multilayer systems. In the case of a 1 nm Ta2O5 single layer on SiO2, the primary ion energy dependence of the decay length was measured. It could be reproduced with the Monte Carlo simulation results. We observed that the depth resolution improved at higher energy rather than at lower energy in contrast to other generally observed cases. It showed that the deeper collision cascade minimized the ion beam mixing at the ultra-thin surface layer and improved the decay length at higher primary ion energy.

Purpose. To describe the CT features of complicated pleural tuberculosis in children and to define the use of CT in children with pleural tuberculosis. Materials and methods. The CT findings in 11 children with complicated pleural tuberculosis were retrospectively analysed. CT was performed to evaluate persistent pleural thickening (n = 6) or a mass-like lesion (n = 5) detected on plain radiographs. Chest radiographs and medical records were reviewed to determine whether additional information provided by CT had altered clinical management. Results. On CT, more than one location was involved in five patients (45 %) and in two patients (18 %) the entire pleural spaces were involved. Pleural thickening was seen in all 11 patients and enhancement after administration of contrast medium occurred in ten patients (91 %). Low-density fluid collections were seen in nine patients (82 %) and in two, CT revealed fluid collections within calcified pleural lesions. In five patients with mass-like lesions on plain radiographs, CT showed a low-density pleural mass with peripheral enhancement in four and a calcified pleural mass with fluid collection in one. CT demonstrated parenchymal abnormalities on the same side as pleural lesions in all 11 patients and hilar or mediastinal adenopathy in four. Four patients (36 %) underwent surgery because of fluid within a calcified fibrothorax (n = 3) and chest wall tuberculosis (n = 1) that were seen only on CT. Conclusions. The CT features of complicated pleural tuberculosis in children were pleural thickening, enhancement and fluid collection with associated parenchymal abnormalities and lymphadenopathy. In the evaluation of children with pleural tuberculosis, CT can be useful for demonstrating fluid within a calcified fibrothorax or chest wall involvement, which usually requires surgical intervention.

We present two cases of granulocytic sarcoma of the cervical lymph nodes with central necrosis as an initial manifestation of childhood leukaemia, focusing on the imaging features. Recognition of the CT and MR imaging findings of granulocytic sarcoma involving the cervical lymph nodes assists the differential diagnosis of noninfective lymphadenopathy in children.