• Childhood Kidney Diseases
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• v.7 no.2
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• pp.181-188
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• 2003

Purpose : Vesicoureteral reflux(VUR) is known to be the main cause of childhood hypertension and renal failure. Knowing its familial occurrence, we determined the incidence of VUR and renal scar in asymptomatic siblings of Korean patients with primary VUR Methods : A total of 50 siblings from 37 index patients were included. Voiding cystourethro-graphy(VCUG) and renal scintigraphy using $^{99m}Tc-DMSA$ were peformed in these siblings from June, 1994 to May, 2001, Index patients were classified into two groups according to the presence of VUR in their siblings, and the clinical factors of the index patients such as age, sex, grade of reflux and renal cortical defect were compared between the groups. Results : Among the 50 siblings, VUR were found in 8(16%) and renal cortical defects were detected in 8(16%) siblings respectively. The incidence of renal cortical defects was 87.5%(7 out of 8) in the VUR(+) siblings. There was a case of VUR(-) cortical defect in one sibling, presumed as a scar from an old VUR. There was no relationship among age, sex, grade of reflux and renal cortical defect of the index patient to the presence of VUR in siblings. Conclusion : This study confirmed a significant incidence of VUR(16%) and renal cortical defects(16%) in the asymptomatic siblings of patients with primary VUR in Korea. It Is resonable to recommend screening studies to the siblings of patients with VUR for the early detection and prevention of probable reflux nephropathy. (J K orean Soc Pediatr Nephrol 2003;7:181-188)

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.3
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• pp.254-259
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• 2014

A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter ${\times}$ 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the $D_2O$ heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.493-501
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• 1996

To assess contribution of T1-201 rest-24 hour delay redistribution in detection of viable myocardium, we studied the predictive value of this redistribution in 17 patients who peformed rest-24 hour delay perfusion SPECT before bypass surgery. Regional wall motion was compared with gated SPECT in 10 patients and echocardiography in 7 patients before and after bypass surgery. Rest and 24 hour delayed uptakes were scored from 0 (normal perfusion) to 3 (defect). In rest SPECT, 56 segments showed perfusion decrease. Thirty four segments(61%) improved after surgery and were defined as viable Nineteen(34%) segments had more uptake of T1-201 at 24 hour delay, and the other 37 segments did not. In 81%(25/31) of segments with mildly decreased perfusion, wall motion after bypass surgery improved, 57% (8/14) of segments with severely decreased perfusion improved, and 9%(1/11) of segments with defects improved. In 14 among 19 segments which had more T1-201 uptakes at 24 hour delay, wall motion was improved(positive predictive value of redistribution: 74%). 20 among 37 segments which had persistent decreases in rest-24 hour redistribution improved and 17 did not(negative predictive value: 46%). Segments having severe perfusion decrease or defects showed improved wall motion after surgery in 64%(7/11), if it had redistribution at delay. Segments with either mildly decreased uptake in resting or rest-delayed redistribution showed improved wall motion in 76%(32/42). Among the 14 segments which showed improvement in wall motion, 10 had partial reversibility in stress-rest images and the other 4 had persistent perfusion defects in stress-rest images. These 4 segments were found viable only with rest-24 hour delayed perfusion SPECT. We concluded that rest T1-201 uptake or redistribution at 24 hour delay should be referred as an evidence to warrant postoperative improvement of abnormal wall motion and we could predict myocardial viability with preoperative rest-24 hour delay perfusion SPECT in the segments with rest perfusion decreases.

• The Korean Journal of Nuclear Medicine
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• v.32 no.2
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• pp.129-136
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• 1998

Purpose: Myocardial SPECT is an effective test for detecting coronary artery disease in the general population. But the diagnostic accuracy between sexes is not defined. The purpose of this study is to compare the diagnostic accuracy between males and females. Materials and Methods: One hundred and seventy seven male and 98 female patients who underwent myocardial SPECT within 1 month of coronary angiography were studied. Myocardial SPECTS were considered abnormal if fixed or reversible perfusion defects were detected. Stenosis severity of ${\geq}$ 50% luminal diameter reduction of any artery defined coronary artery disease (CAD). Results: Overall sensitivity for detection of CAD was 98% in men and 97% in women (p=not significant). However, specificities, accuracies, and positive predictive values (PPV) in men and women were 49% vs 31% (p<0.05), 81% vs 57% (p<0.01), 78% vs 48% (p<0.01), respectively. Diagnostic accuracies for detection of right coronary artery disease were not different in both sexes, however, accuracies for detection of left anterior descending artery disease and left circumflex artery disease were significantly lower in female (p<0.05). Conclusion: A significant difference of diagnostic accuracy between sexes, especially in LAD and LCx disease, was noted. Artifacts from breast attenuation might be a cause for the lower diagnostic accuracy in female.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.15-20
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• 2008

Purpose : Large exon deletions in the DMD gene are found in about 60% of DMD/BMD patients. Multiplex PCR has been employed to detect the deletion mutation, which frequently generates noise PCR products due to the presence of multiple primers in a single reaction as well as the stringency of PCR conditions. This often leads to a false-negative or false-positive result. To address this problematic issue, we introduced the dual primer oligonucleotide (DPO) system. DPO contains two separate priming regions joined by a polydeoxyinosine linker that results in high PCR specificity even under suboptimal PCR conditions. Methods : We tested 50 healthy male controls, 50 patients with deletion mutation as deletion-positive patient controls, and 20 patients with no deletions as deletion-negative patient controls using DPO-multiplex PCR. Both the presence and extent of deletion were verified by simplex PCR spanning the promoter region (PM) and 18 exons including exons 3, 4, 6, 8, 12, 13, 17, 19, 43-48, 50-52, and 60 in all 120 controls. Results : DPO-multiplex PCR showed 100% sensitivity and specificity for the detection a deletion. However, it showed 97.1% sensitivity and 100% specificity for determining the extent of deletions. Conclusion : The DPO-multiplex PCR method is a useful molecular test to detect large deletions of DMD for the diagnosis of patients with DMD/BMD because it is easy to perform, fast, and cost-effective and has excellent sensitivity and specificity.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.427-436
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• 2001

Objective : To estimate the prevalence of congenital heart disease from the 1990 student heart disease screening program. Methods : The heart disease screening program for elementary students was conducted in Kyonggi-do, in 1998. The subjects of the present study comprised the 40,402 students who attended the schools in the catchment area of a collaborative university hospital and who participated in the primary examination. The congenital heart disease (CHD) patients were initially identified through a questionnaire about prior medical history, and further through diagnostic tests & medical examinations in the secondary & the tertiary examinations. Certain assumptions were used in the estimation of the number of CHD cases among non-participants of the secondary & tertiary examinations. The overall prevalence of CHD was estimated by adding the CHD detection rates of the participants and the estimated prevalence of the non-participants. Results : Among the 40,402 primary participants, 1,655 were referred further, of whom 79.1% (1,309) participated in the secondary examination. Of these, 121 were referred to the tertiary examination, with a participation rate at this last stage of 80.2%. The positive predictive value (PPV) of the screening tools was the highest when the results of both EKG and the questionnaire were positive. Because 85.9% of the detected cases had a past history of CHD, PPV was higher when the selection criteria in the questionnaire included past CHD history than when it didnt. The CHD defection rate among the participants was 1.76 cases/1,000 and the presumed number of cases among the non-participants was 31; giving an estimated final CHD prevalence of 2.52 cases/1,000 (95% CI : 2.06-3.06). Among the identified cases of CHD, VSD (52.8%) was the most common, followed by PDA (9.7%), TOF (9.7%) & PS (9.7%). Conclusion : Because the characteristics of the non-participants differed from those of the participants, the estimation of prevalence was influenced by the participation rate. Of the detected cases, 85.9% had a past history of diagnosis or operation for CMD. These findings suggested that the prevalence estimated in this study may be an underestimation of the actual condition. Therefore, a birth cohort study is required in order to more accurately estimate the prevalence and the effects of the program.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.210-217
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• 1993

To compare the myocardial viability in patients suffering from total occlusion of the right coronry artery (RCA) with the angiographic collaterals, intracoronary injection of Thallium-201 (T1-201) was done to 14 coronary artery disease (CAD) patients (pts) with total occlusion of RCA and into four normal subjects for control. All 14 CAD pts had Grade 2 or 3 collateral circulations. There were 14 male and 4 females, and their ages ranged from 31 to 70 years. In nine pts, T1-201 was injected into left main coronary artery (LCA) ($300{\sim}350{\mu}Ci$) to evaluate the myocardial viability of RCA territory through collateral circulations. The remaining five pts received T1-201 into RCA ($200{\sim}250{\mu}Ci$) because two had intraarterial bridging collaterals and three had previous successful PTCA. Planar & SPECT myocardial perfusion images were obtained 30 minutes, and four to five hours after T1-201 injection. Intravenous T1-201 reinjection (six pts) or $^{99m}Tc-MIBI$ (two pts) were also performed in eight CAD pts. Intracoronary myocardial perfusion images were compared with intravenous T1-201 (IV T1-201) images, ECG, and ventriculography. Intracoronary T1-201 images proved to be superior to that of IV T1-201 due to better myocardial to background uptake ratio and more effective in the detection of viable tissue. We also found that perfusion defects were smaller on intracoronary T1-201 images than those on the IV T1-201. All of the 14 CAD pts had either mostly viable myocardium (seven pts) or large area of T1-201 perfusion (seven pts) in RCA territory, however ventriculographic wall motion and ECG did not correlate well with intracoronary myocardial perfusion images. In conclusion, total RCA occlusion patients with well developed collateral circulation had large area of viable myocardial in the corresponding territory.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.89-97
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• 1994

Although bone scan is a highly sensitive test for detecting bone metastasis, its findings are often limited in specificity and cannot be used for assessing the bone marrow. Bone marrow scintigraphy may provide useful information but previous experience with radiolabelled colloid has been disappointing. Recently, $^{99m}Tc$ labeled anti-granulocyte monoclonal antibody (anti-NCA-95 MAb) has been introduced as a new bone marrow imaging agent. To evaluate the usefulness of $^{99m}Tc$ anti-NCA MAb bone marrow scans for detecting skeletal metastasis, bone marrow scans of 44 malignant tumor patients were evaluated and compared with bone scan findings. Bone scan showed abnormal lesions in 26(59%) cases, and 18 of these patients also had an abnormal bone marrow scan. Seven of the 8 patients who had normal bone marrow scan despite bone scan lesions were confirmed to be free from metastasis. There was one case with a marrow defect despite normal bone scan but the presence of metastasis was not determined due to loss of follow up. Bone scan demonstrated a total of 64 lesions while bone marrow scan showed 38 lesions. Fifty percent (32/64) of the bone scan lesions had matching marrow defects while the remaining 50% did not. Most of these non matched lesions were suggested to be nonspecific lesions such as rib fractures or degenerative change. Meanwhile bone marrow scan was able to detect 6 new lesions not detected by bone scan, bit metastasis in each lesion was not confirmed. Bone marrow scan was also helpful in assessing equivocal bone scan lesions to be of metastatic nature in 10 patients by demonstrating a matched marrow defect. Thus $^{99m}Tc$ anti-NCA MAb bone marrow scan can help exclude metastasis in patients with nonspecific bone scan lesions and may be able to detect metastatic lesions not seen with bone scan. It appears useful as a complementary study to bone scan in evaluating malignant tumor patients.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1301-1307
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• 2006

Purpose : Hearing loss is one of the most common birth defects, and early detection and intervention positively impact language/speech and cognitive development. It has been reported that NICU graduates have a high incidence of hearing loss. So we investigated the incidence, risk factors and clinical outcome of hearing loss in NICU graduates. Methods : This study involved neonatal auditory brainstem response (ABR) testing of newborn infants who graduated from the NICU of Kyungpook National University Hospital during a 3-year period (between July 2002 and June 2005) and subsequent follow-up of these infants. Results : ABR evaluations were performed on 474 infants. Of these infants, 64 showed abnormal ABR (13.5 percent). Of 128 ears from these 64 infants, two ears (1.6 percent) and 10 ears (7.8 percent) were classified as severe and profound hearing loss, respectively. The infants with abnormal ABR had higher incidence of prematurity, low birth weight, very low birth weight, neonatal asphyxia, cranio-facial malformation and amikacin treatment over 15 days (P<0.05). In infants with hyperbilirubinemia, the peak level of serum bilirubin, duration of phototherapy and exchange transfusion were not associated with the higher incidence of hearing loss. Follow-up ABR evaluation was performed on 15 infants with abnormal ABR at $8.8{\pm}4.4months$. In follow-up ABR, 80.0% showed improvement or normalization of threshold sensitivity. Conclusion : NICU graduates exhibit high risk for hearing loss. Systemic and effective hearing assessment program is needed for these high risk infants.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.124-131
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• 2009

A reliable detection of regions in radiography is one of the most important task before the evaluation of defects on welded joints. The extracted features is to be classified into distinctive clusters for each segmented region. But conventional segmentation techniques give unsatisfactory results for this task due to the spatial superposition of intensity and low signal-to-ratio(SNR) in radiographic images. The usage of global or local processes not only provide the necessary noise resistance but also fail in classification of regions. In this paper, we presents an appropriate approach for segmentation of region-based indications in industrial Computed Radiography(CR) images. The geometric differences between welded and non-welded area which is generated on radiography as the representative regions(background, thickness, middle and welded region in steel tube image) have constructed the hierarchical structure. Although this structure is contaminated by noise, the scheme between regions can be selected by the help of local clustering based on distinctive geometric property of each region. Because of the geometric nature of the considered region and so that the region is selected layer by layer, and that the real class represents the boundary between regions, the vertical and horizontal clustering process in each layer must be judicious. In order to show the effectiveness of this approach, a comparative experiment of various segmentation method is performed on industrial steel tube CR images.