• Journal of radiological science and technology
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• v.39 no.2
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• pp.149-156
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• 2016

Measurement of cardiac blood flow using the magnetic resonance imaging has been limited due to breathing and involuntary movements of the heart. The present study attempted to improve the accuracy of cardiac blood flow testing through phase contrast magnetic resonance imaging by presenting the adequate breathing method and imaging variables by comparing the measurement values of cardiac blood flow. Each was evaluated by comparing the breath hold retrospective 1NEX and non breath hold retrospective 1-3NEX in the ascending aorta and descending aorta. As a result, the average blood flow amount/velocity of the breath hold retrosepctive 1NEX method in the ascending aorta were $96.17{\pm}19.12ml/sec$, $17.04{\pm}4.12cm/sec$ respectively, which demonstrates a statistically significant difference(p<0.05) with the non-breath hold retrospective method 1NEX of $72.31{\pm}13.27ml$ and $12.32{\pm}3.85$. On the other hand, the average 2NEX blood flow and mean flow velocity is $101.90{\pm}24.09$, $16.84{\pm}4.32$, 3NEX $103.06{\pm}25.49$, $16.88{\pm}4.19$ did not show statistically significant differences(p>0.05).The average blood flow amount/ velocity of the breath hold retrospective 1NEX method in the descending aorta were $76.68{\pm}19.72ml/s$, and $22.23{\pm}4.8$, which did not demonstrate a significant difference in comparison to non-breath hold retrospective method 1-3 NEX. Therefore, the non breath hold retrospective method does not significantly differ in terms of cardiac blood flow in comparison with the breath hold retrospective method in accordance with the increase of NEX, so pediatric patients or patients who are not able to breathe well must have the diagnostic value of their cardiac blood flow tests improved.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.870-874
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• 2006

Purpose : Popular use of fetal ultrasonography has increased to detect congenital hydronephrosis(CH) which is the most common anomaly prenatally detected. We'd like to determine the frequency and clinical characteristics of prenatally diagnosed CH and outcome of ureteropelvic junction stenosis(UPJS). Methods : The records of births between January 1994 and June 2003 in Chonnam National University Hospital(CNUH), and the records of children who were diagnosed with CH in the Department of Pediatrics of CNUH during the above period, were retrospectively analyzed. In the patients with UPJS, the initial anterior posterior diameters of renal pelvis(APD) were compared between the spontaneous regression (SR) and operation group(OP). In the SR group, sequential regression rates of APD were estimated. Results : Among a total 9,076 births, 231(2.54 percent) patients with 293 renal units were diagnosed as CH and 19(6.78 percent) renal units spontaneously regressed 3 days after birth. In 228 children(56 bilateral; 172 unilateral; total 284 renal units) diagnosed with CH in the department of pediatrics of CNUH, male(71.9 percent) and left kidney(69.2 percent) predilection were found and 78.1 percent of CH were caused by UPJS. The initial APD of the SR group(121 units) in UPJS was $7.8{\pm}6.28mm$, which was significantly smaller than the APD($26.8{\pm}12.14mm$) of the OP group(25 unit)(P<0.05). In the SR group, 81 percent spontaneously regressed within one year. Conclusions : In CH, male and left kidney predilection were found. UPJS was the most common cause of CH and initial APD in UPJS at 3 days of age was a good prognostic indicator. Close monitoring should be done for at least one year because most SR in UPJS regressed spontaneously within one year.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.298-304
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• 2006

Purpose : We compared the asthma predictive index(API) and the modified asthma predictive index (mAPI) of the Tuscon Children's Respiratory Study Group in Korean children with recurrent wheezing. We investigated the atopic profiles and presence of allergen sensitization of each risk group, and ascertained the significant clinical risk factors. Methods : Two hundred and sixty two children, who visited for recurrent wheezing from 1998 to 2005, were enrolled and divided into groups by API and mAPI. We investigated the history of the patients and their families, atopic profiles, and sensitization to aeroallergen and food allergens. Twenty nine children were followed up to 6 years of age and we evaluated the sensitivity, specificity and positive and negative predictive value of both indices. Results : The high risk group of API were of older age, were more likely to be sensitized to aeroallergen(P=0.001) and food allergen(P=0.034) and had higher levels of total eosinophil count, eosinophil percent, serum ECP, total IgE, and D.p-, D.f-specific IgE. High risk group of mAPI showed higher levels of atopic markers such as egg-, milk-, D.p- and D.f-specific IgE. Even though API did not include allergen sensitization, the high risk group was more significantly sensitized to common allergens than the low risk group. Twenty nine children were followed up until 6 years of age; therefore 15 children were diagnosed as asthma, clinically. The sensitivity, specificity, positive and negative predictive values of mAPI were higher than API. Conclusion : Both high risk groups of API and mAPI had higher levels of atopic markers and were more sensitized to common allergens. These findings suggest that sensitization to aeroallergens and food allergens are more objective markers as asthma predictive indices. In addition, mAPI is a more reliable index in predicting asthma in Korean children with recurrent wheezing than is API. But only 29 patients were followed until the age of 6, so we need to include more children with long term follow up for future study.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.961-966
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• 2002

Purpose : We compared the underlying or associated diseases according to the frequency of platelet transfusions in neonates with thrombocytopenia to know the factors predicting which patients will require multiple platelet transfusions. We also compared mortality. Methods : A retrospective study was performed in 72 neonates who received the platelet transfusions in neonatal intensive care unit(NICU) between August 1996 and July 2001. Group I received one platelet transfusion and group II received two or more. We compared the frequency of underlying or assodiated diseases such as sepsis/disseminated intravascular coagulopathy(DIC), respiratory distress syndrome(RDS), intraventricular hemorrhage(IVH), patent ductus arteriosus (PDA), necrotizing enterocolitis(NEC), liver or renal disease, and mortality between two groups. Results : Of the 72 patients, 29(40.2%) received one and 43(59.7%) received two or more transfusions; 16(22.2%) received four or more. There were no statistically significant differences in gestational age, birth weight, sex, and maternal history between two groups. C-section rate was higher in group II(20.7% vs. 55.8%, P<0.05) and the incidence of PDA was higher in group I (55.2% vs. 30.2%, P<0.05). Otherwise, there were no statistically significant differences in the incidence of sepsis/DIC, RDS, IVH, RDS, CLD, NEC, liver or renal disease, pulmonary hemorrhage and hypoxic ischemic encephalopathy, and mortality between group I and group II. Conclusion : There was no significant difference in clinical morbidity and mortality according to the frequency of platelet transfusion in neonates with thrombocytopenia. Further study is needed to know the predicting factor for multiple platelet transfusions in neonates with thrombocytopenia.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1090-1096
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• 2002

Purpose : We evaluated the clinical manifestations, bronchoscopic findings and therapeutic effects of flexible fiberoptic bronchoscopy in atelectasis of children. Methods : Sixty six children who received bronchoscopy due to persistent atelectasis, acute severe atelectasis and incidental atelectasis on plain chest radiography were studied retrospectively. Results : The most common causative underlying disease was pneumonia(60.4%). Other underlying conditions were pulmonary tuberculosis, chronic lung disease, postoperative state, bronchial asthma and chest trauma. The most common abnormal findings were inflammatory changes such as bronchial stenosis(n=15), mucosal edema and large amount of secretion(n=14), granulation tissue( n=3) and mucus plug(n=3) although 39.4% showed normal airways. Other findings were congenital airway anomalies, endobronchial tuberculosis, extrinsic compression and obstruction by blood clot. In 32 children with pneumonia-associated atelectasis, 43.7% revealed normal airways, and the most common abnormal findings were also inflammatory changes. Eighteen out of 39 patients who received therapeutic intervention such as suctioning of secretion, bronchial washing and intrabronchial administration of N-acetylcysteine($Mucomyst^{(R)}$) had complete or partial resolution of their atelectasis. In 32 patients with pneumonia-associated atelectasis, 56.5% showed improvement by therapeutic intervention. Conclusion : In this study, atelectasis was mainly associated with inflammatory airway diseases such as pneumonia. The most common abnormal bronchoscopic findings were inflammatory changes such as mucosal edema and large amounts of secretion and bronchial stenosis, although about 40% revealed normal airway. Flexible bronchoscopy is helpful for either diagnosis or treatment, especially in pneumonia-associated atelectasis.

• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.72-79
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• 2010

Purpose: Left ventricular (LV) hypertrophy and impaired diastolic function may occur early in systemic hypertension. Diastolic dysfunction is associated with increased cardiovascular risk. Tissue Doppler imaging (TDI)-derived tissue velocity and strain rate are new parameters for assessing diastolic dysfunction. The aim of this study is to determine whether TDI and strain rate imaging (SRI) would improve the ability to recognize early impaired diastolic and systolic functions compared with conventional echocardiography in hypertensive adolescents. Methods: We included 38 hypertensive patients with systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg. Ejection fraction and myocardial performance index (MPI) were estimated by conventional echocardiography. Peak systolic myocardial velocity, early diastolic myocardial velocity (Em), and peak late diastolic myocardial velocity (Am) were obtained by using TDI and SRI. Results: In the hypertensive group, interventricular septal thickness was significantly increased on M-mode echocardiography. Em/Am was significantly decreased at the mitral valve annulus. Among hypertensive subjects, the E strain rate at basal, mid, and apex was significantly decreased. Systolic strain was significantly decreased at the septum in the hypertensive group. Conclusion: Strain rate might be a useful new parameter for the quantification of both regional and global LV functions and could be used in long-term follow up in hypertensive patients. Early identification by SRI of subjects at risk for hypertensive and ventricular dysfunction may help to stratify risk and guide therapy. Further studies, including serial assessment of LV structure and function in a larger number of adolescents with hypertension, is necessary.

• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.474-480
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• 2008

Purpose : Stress hyperglycemia is common in critically ill adult patients. It is known as a predictor of increased mortality, and intensive insulin therapy has been shown to improve the prognosis in such patients. We have investigated the relationship between early stress hyperglycemia and clinical outcomes in preterm infants. Methods : In this study, 141 preterm infants with a gestational age of less than 30 weeks were enrolled. The hyperglycemic group was defined as that having maximum glucose of more than 150 mg/dL (n=61) during the first 48 h of life, and the non-hyperglycemic group was defined as that having maximum glucose of less than 150 mg/dL (n=80). Perinatal history, severity of illness using the Clinical Risk Index for Babies (CRIB) score, clinical outcomes, and mortality of the two groups were compared. Results : There was no significant difference in the gestational age between the two groups, but the birth weight (P<0.001) was significantly lower, and the CRIB score (P<0.001) was significantly higher in the hyperglycemic group. Disseminated intravascular coagulation (P<0.001) and clinically suspected sepsis (P=0.046) were more common in the hyperglycemic group. Mortality was markedly higher in the hyperglycemic group (11.3% vs. 41.0%, P<0.001). On performing a stepwise multiple logistic regression analysis, hyperglycemia (OR 3.787; 95% CI 1.324 to 10.829), the CRIB score (OR 1.252; 95% CI 1.047 to 1.496) and birth weight (OR 0.997; 95% CI 0.994 to 1.000) was independently associated with higher mortality. Conclusion : Stress hyperglycemia within the first 48 h of life is independently related to increased morbidity and mortality in preterm infants.

• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.487-491
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• 2008

Purpose : Although Mycoplasma pneumoniae (M. pneumoniae) infection can cause wheezing in non-asthmatic children, the mechanisms of this symptom remain unclear. Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis and vascular permeability, and is also known to be elevated in cases of chronic pulmonary disease such as asthma. We hypothesized that VEGF may increase in children with acute M. pneumoniae pneumonia and wheezing. Methods : Nine patients with clinical and laboratory evidence of acute M. pneumoniae pneumonia were enlisted from children admitted to Korea University Hospital. They had had more than one episode of wheezing during the illness, which was confirmed by a physician; they comprised the wheezer group. The individuals with M. pneumoniae pneumonia without wheezing were 63 in number, and they comprised the non-wheezer group. Patients with a history of asthma or who had received asthma medications were excluded. Serum concentrations of VEGF, total IgE, eosinophil cationic protein (ECP), and peripheral blood eosinophil counts were measured. Results : The serum VEGF concentrations were higher in the wheezer group ($mean{\pm}SD$; $650.2{\pm}417.9pg/mL$) than in the non-wheezer group ($376.5{\pm}356.2pg/mL$, P=0.049). M. pneumoniae antibody (1:1,380 vs. 1:596, P=0.048) and serum total IgE (591.8 IU/mL vs. 162.2 IU/mL, P=0.032) were higher in the wheezer group than in the non-wheezer group. There were no differences between the two groups in terms of serum ECP concentration or blood eosinophil count. Conclusion : In the presence of wheezing, serum VEGF concentrations were higher in the children with M. pneumoniae pneumonia. This finding suggests that VEGF may associate with wheeze-related symptoms in children with acute M. pneumoniae pneumonia.

• Clinical and Experimental Pediatrics
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• v.50 no.5
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• pp.457-461
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• 2007

Purpose : Urinary tract infection (UTI) is a common bacterial infectious disease in childhood. Especially UTI in infant and young children is associated with urinary tract anomalies such as hydronephrosis, vesicoureteral reflux. The aim of this study was to compare the clinical and laboratory characteristics, and uroradiologic findings of UTI caused by pathogens other than E. coli with UTI caused by E. coli in infant and young children. Methods : We retrospectively reviewed medical records of 170 infants and children, who had been admitted for UTI to Il Sin Christian Hospital from January 2003 to December 2005. All patients were divided into two groups; E. coli and non-E. coli UTI, and they were compared for demographic data, clinical data (degree and duration of fever, time to defervescence, and length of hospital stay), underlying urinary tract anomalies (by history and ultrasonography), recurrent infection (by history and past medical records), and laboratory data [urinalysis, white blood cells (WBC) count in peripheral blood, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum creatinine level]. Results : Of the 170 UTI patients, the number of non-E. coli UTI was 114 (67.1%) and E. coli UTI was 56 (32.9%). As compared to E. coli group, non-E. coli group was younger in age ($0.52{\pm}0.59years$ vs $0.84{\pm}1.39years$, P<0.05), had higher rates of urinary tract anomalies [n=46 (82.1%) vs n=53 (46.5%), P<0.001], higher recurrence rate, shorter time to defervescence, less peripheral blood WBC count, lower level of CRP, lower level of ESR. Conclusion : The characteristics of non-E. coli UTI compared to E. coli UTI was younger age, milder clinical symptoms and signs, higher rates of urinary tract anomalies and higher recurrence rate.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.152-160
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• 1998

Purpose : Vesicoureteral reflux (VUR), which can result in renal failure in children, is expected to resolve spontaneously in mild cases, but severe cases require surgical correction, posing dilemma in deciding the right measures in some cases. Therefore, to delineate the factors affecting spontaneous resolution of VUR and to apply them in assessing the prognosis, we reviewed the patients with VUR who had been treated medically. Patients and Methods : 32 children (49 renal units) with reflux who had been admitted during the 5-year period from Jan '92 to Dec '96 were classified into 4 groups (Resolved, Improved, Unchanged, and Worsened) and analyzed. Results : 1) 25 were boys and 7 girls. The age at diagnosis ranged from 13 days to 9 years (mean $24.6{\pm}11.4$ mo) 2) Among 49 refluxing ureters, 4 were below 1 me of age,21 between 1 me to 1 yr, 16 between 1 yr to 6 yr, 8 beyond 6 yr. Two belonged to Grade I, 16 to Crade II, 17 to Grade III, 12 to Grade IV, and 2 to Grade V. 3) Spontaneous resolution rates of reflux were 100, 81, 47, 8, 0$\%$ for each Grade, respectively. Resolution plus improvement rates in Grade III and IV were 71 and $50\%$, each. 4) Resolution rates in relation to the age at diagnosis were $100\%$ for below 1 mo, $48\%$ between 1 mo to 1 yr, $56\%$ between 1 to 6 yr, and $13\%$ beyond 6 yr. 5) Of 15 unilateral refluxing ureters, 14 ($93\%$) resulted in resolution. Of 34 bilateral refluxing ureters, 11 ($32\%$) resolved spontaneously 6) Resolution occurred within 1 year in 20 units of 24 renal units in regular follow-up. Conclusion: The lower the initial grade and the younger the patient, the sooner the reflux resolved. Resolution was better when VUR was unilateral than bilateral. Long-term regular follow-up is essential because even the cases falling in Grades III and IV have high rates of spontaneous resolution and improvement with medical treatment.