• Korean Journal of Radiology
• /
• v.20 no.4
• /
• pp.662-670
• /
• 2019

Objective: A developmental venous anomaly (DVA) is a vascular malformation of ambiguous clinical significance. We aimed to quantify the susceptibility of draining veins (χ_vein) in DVA and determine its significance with respect to oxygen metabolism using quantitative susceptibility mapping (QSM). Materials and Methods: Brain magnetic resonance imaging of 27 consecutive patients with incidentally detected DVAs were retrospectively reviewed. Based on the presence of abnormal hyperintensity on T2-weighted images (T2WI) in the brain parenchyma adjacent to DVA, the patients were grouped into edema (E+, n = 9) and non-edema (E-, n = 18) groups. A 3T MR scanner was used to obtain fully flow-compensated gradient echo images for susceptibility-weighted imaging with source images used for QSM processing. The χ_vein was measured semi-automatically using QSM. The normalized χ_vein was also estimated. Clinical and MR measurements were compared between the E+ and E- groups using Student's t-test or Mann-Whitney U test. Correlations between the χ_vein and area of hyperintensity on T2WI and between χ_vein and diameter of the collecting veins were assessed. The correlation coefficient was also calculated using normalized veins. Results: The DVAs of the E+ group had significantly higher χ_vein (196.5 ± 27.9 vs. 167.7 ± 33.6, p = 0.036) and larger diameter of the draining veins (p = 0.006), and patients were older (p = 0.006) than those in the E- group. The χ_vein was also linearly correlated with the hyperintense area on T2WI (r = 0.633, 95% confidence interval 0.333-0.817, p < 0.001). Conclusion: DVAs with abnormal hyperintensity on T2WI have higher susceptibility values for draining veins, indicating an increased oxygen extraction fraction that might be associated with venous congestion.

• Geophysics and Geophysical Exploration
• /
• v.27 no.2
• /
• pp.119-128
• /
• 2024

Marine magnetic surveys provide a rapid and cost-effective method for pioneer geophysical survey for many purposes. Sea-surface magnetometers offer high accuracy but are limited to measuring the scalar total magnetic field and require dedicated cruise missions. Shipboard three-component magnetometers, on the other hand, can collect vector three components and applicable to any cruise missions. However, correcting for the ship's magnetic field, particularly viscous magnetization, still remains a challenge. This study proposes a new additional correction method for ship's viscous magnetization effect in vector data acquired by shipboard three-component magnetometer. This method utilizes magnetic data collected simultaneously with a sea-surface magnetometer providing total magnetic field measurements. Our method significantly reduces deviations between the two datasets, resulting in corrected vector anomalies with errors as low as 7-25 nT. These tiny errors are possibly caused by the vector magnetic anomaly and its related viscous magnetization. This method is expected to significantly improve the accuracy of shipborne magnetic surveys by providing corrected vector components. This will enhance magnetic interpretations and might be useful for understanding plate tectonics, geological structures, hydrothermal deposits, and more.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.1
• /
• pp.5-19
• /
• 1998

Introduction: Direct histologic and bacteriologic examination of a representative specimen of lung tissue is the only certain method of providing an accurate diagnosis in various pulmonary diseases including diffuse pulmonary diseases. The purpose of national survey was to define the indication, incidence, effectiveness, safety and complication of open and thoracoscopic lung biopsy in korea. Methods: A multicenter registry of 37 university or general hospitals equipped more than 400 patient's bed were retrospectively collected and analyzed for 3 years from the January 1994 to December 1996 using the same registry protocol. Results: 1) There were 511 cases from the 37 hospitals during 3 years. The mean age was 50.2 years(${\pm}15.1$ years) and men was more prevalent than women(54.9% vs 45.9%). 2) The open lung biopsy was performed in 313 cases(62%) and thoracoscopic lung biopsy was performed in 192 cases(38%). The incidence of lung biopsy was more higher in diffuse lung disease(305 cases, 59.7%) than in localized lung disease(206 cases, 40.3%) 3) The duration after abnormalities was found in chest X-ray until lung biopsy was 82.4 days(open lung biopsy: 72.8 days, thoracoscopic lung biopsy: 99.4 days). The bronchoscopy was performed in 272 cases(53.2%), bronchoalveolar lavage was performed in 123 cases(24.1%) and percutaneous lung biopsy was performed in 72 cases(14.1%) before open or thoracoscopic lung biopsy. 4) There were 230 cases(45.0%) of interstitial lung disease, 133 cases(26.0%) of thoracic malignancies, 118 cases(23.1%) of infectious lung disease including tuberculosis and 30 cases (5.9 %) of other lung diseases including congenital anomalies. No significant differences were noted in diagnostic rate and disease characteristics between open lung biopsy and thoracoscopic lung biopsy. 5) The final diagnosis through an open or thoracoscopic lung biopsy was as same as the presumptive diagnosis before the biopsy in 302 cases(59.2%). The identical diagnostic rate was 66.5% in interstitial lung diseases, 58.7% in thoracic malignancies, 32.7% in lung infections, 55.1 % in pulmonary tuberculosis, 62.5% in other lung diseases including congenital anomalies. 6) One days after lung biopsy, $PaCO_2$ was increased from the prebiopsy level of $38.9{\pm}5.8mmHg$ to the $40.2{\pm}7.1mmHg$(P<0.05) and $PaO_2/FiO_2$ was decreased from the prebiopsy level of $380.3{\pm}109.3mmHg$ to the $339.2{\pm}138.2mmHg$(P=0.01). 7) There was a 10.1 % of complication after lung biopsy. The complication rate in open lung biopsy was much higher than in thoracoscopic lung biopsy(12.4% vs 5.8%, P<0.05). The incidence of complication was pneumothorax(23 cases, 4.6%), hemothorax(7 cases, 1.4%), death(6 cases, 1.2%) and others(15 cases, 2.9%). 8) The 5 cases of death due to lung biopsy were associated with open lung biopsy and one fatal case did not describe the method of lung biopsy. The underlying disease was 3 cases of thoracic malignancies(2 cases of bronchoalveolar cell cancer and one malignant mesothelioma), 2 cases of metastatic lung cancer, and one interstitial lung disease. The duration between open lung biopsy and death was $15.5{\pm}9.9$ days. 9) Despite the lung biopsy, 19 cases (3.7%) could not diagnosed. These findings were caused by biopsy was taken other than target lesion(5 cases), too small size to interpretate(3 cases), pathologic inability(11 cases). 10) The contribution of open or thoracoscopic lung biopsy to the final diagnosis was defininitely helpful(334 cases, 66.5%), moderately helpful(140 cases, 27.9%), not helpful or impossible to judge(28 cases, 5.6%). Overall, open or thoracoscopic lung biopsy were helpful to diagnose the lung lesion in 94.4 % of total cases. Conclusions: The open or thoracoscopic lung biopsy were relatively safe and reliable diagnostic method of lung lesion which could not diagnosed by other diagnostic approaches such as bronchoscopy. We recommend the thoracoscopic lung biopsy when the patients were in critical condition because the thoracoscopic biopsy was more safe and have equal diagnostic results compared with the open lung biopsy.

• Clinical and Experimental Pediatrics
• /
• v.52 no.4
• /
• pp.458-463
• /
• 2009

Purpose : Schizencephaly is a uncommon congenital brain anomaly characterized by congenital clefts spanning the cerebral hemispheres from pial surface to lateral ventricles and lined by gray matter. In this study, we investigated the clinical manifestation and radiologic findings of pediatric schizencephaly. Methods : The data of 13 patients who were diagnosed with schizencephaly in Severance Childrens Hospital and Yongdong Severance Hospital from January 2005 to December 2007 were analyzed retrospectively. Results : The mean age at diagnosis was $9.08{\pm}2.67$ months old and ranged from 1 to 30 months. The ratio of male to female patients was 3.33:1. Five (38.5%) patients had bilateral clefts, while 8 (61.5%) had unilateral clefts. Five (38.5%) patients had closed lip clefts, and 4 (30.8%) had opened lip clefts. Four (30.8%) patients had multiple clefts. Associated anomalies showed in all cases. The clinical features consisted of mild unilateral weakness in 7 (53.8%) cases and a hemiparesis was present in 3 (23.1%) patients. A tetraparesis was in 3 (23.1%) patients. There was no difference in motor deficit between unilateral and bilateral clefts. Delayed development was observed in all cases. Epilepsy was present in 7 (53.8%) patients, 5 patients with unilateral clefts and 2 patients with bilateral clefts. Three (42.8%) patients showed intractable seizures. Conclusion : Schizencephaly showed variable clinical manifestations and radiologic findings in association with the types and locations of the clefts. It is necessary to diagnose schizencephaly early and to detect the development of epilepsy. Intensive and large studies of the correlation of clinical outcomes and radiologic findings should be continued for more effective treatment.

• Clinical and Experimental Pediatrics
• /
• v.50 no.6
• /
• pp.543-548
• /
• 2007

Purpose : The anthropometric data of newborns published by Lubchenco et al in the 1960's have been most commonly used in Korea as a standard of newborn growth. We hypothesized that Lubchenco's data have limitations for Korean premature infants born in the 2000's. We analyzed and compared the data of birth weight, length, and head circumference. Methods : The medical records of 1,159 premature infants of 26 to 35 weeks of gestational age born at Il-Sin Christian Hospital of Busan from January 2,000 to August 2,006 were reviewed. The anthropometric data from total 1,010 premature infants were analyzed after excluding the data from infants whose gestational age were estimated by other than ultrasonogram, and infants with major congenital anomalies or chromosomal anomaly, born from foreign parent, and extreme outliers. Results : In the birth weights by gestational age, our 90 percentile values were lower than Lubchenco's 90 percentile values for all gestational age studied, particularly for less than 30 weeks the 90 percentile curve was drawn at the area as that of Lubchenco' 75 percentile. And our 10 percentile values were higher than Lubchenco's 10 percentile values for all gestational age studied. In the birth length and head circumference by gestational age, our 90 percentile values were lower than Lubchenco's 90 percentile values for all gestational age studied, and the 90 percentile curve was drawn at the area as that of Lubchenco's 75 percentile. And our 10 percentile values were higher than Lubchenco's 10 percentile values for all gestational age studied. Conclusion : It is unreasonable to apply Lubchenco's data published before 4th decades to present Korean premature infants and have a risk to underestimate intrauterine growth retardation or small for gestational age and large for gestational age. Considering for the possibility of increasing the mortality and morbidity of premature infants due to delayed diagnosis and treatment by these underestimating, our anthropometric data of premature infant is expected to contribute to lower the mortality and morbidity of premature infants.

• Clinical and Experimental Pediatrics
• /
• v.50 no.11
• /
• pp.1061-1066
• /
• 2007

Purpose : Early identification of developmental disabilities allows intervention at the earliest possible point to improve the developmental potential. The Ages and Stages Questionnaire (ASQ), a parent- completed questionnaire, can be used as a substitute for formal screening tests. The purpose of this study was to evaluate the validity of the Korean version of the ASQ (K-ASQ) as a screening tool for detecting developmental delay of young Korean children in the setting of a busy pediatric outpatient clinic. Methods : Parents completed the K-ASQ in the waiting room of the pediatric outpatient clinic of St. Mary's Hospital, Catholic University Medical College. Out of 150 completed the ASQ, 67 who were born term and had no previous diagnosis of developmental delay, congenital anomalies, or neurological abnormalities were enrolled. The cut-off values of less than 2 standard deviations (SD) below the mean for the ASQ were used to define a "fail", and children who failed in one or more domains tested were classified as "screen-positive". Diagnosis of developmental delay was made when the developmental indices fell below -1 SD of the Bayley Scales of Infant Development-II. Results : (1) The mean age of children was $16.4{\pm}7.4$ months. Ten children (14.9%) were small-for- gestational age infants. The mean birth weight and gestational age were $3.1{\pm}0.6kg$ and $38.8{\pm}1.4$ weeks. Nine children (13.4%) were twins and 33 (49.0%) were male. The mean maternal education in years was $13.6{\pm}2.4$, and 31.3% had full-time jobs. The time for completing the ASQ was $10.2{\pm}3.0$ minutes. (2) Seventeen children (25.4%) were classified as screen-positive, four of them were delayed in development. Among eight children diagnosed with developmental delay, four were screen-positive and the other four were screen-negative by the ASQ. (3) The test characteristics of the ASQ were as follows: sensitivity (50.0%); specificity (78.0%); positive predictive value (23.5%); negative predictive value (92.0%). Conclusion : The high negative predictive value of the K-ASQ supports its use as a screening tool for developmental delay in the setting of a pediatric outpatient clinic.

• Journal of Chest Surgery
• /
• v.38 no.12 s.257
• /
• pp.844-848
• /
• 2005

Background: Thoracic outlet syndrome(TOS) is caused by the compression of neurovascular structures that supply to the upper extremities. Only a few reports have been published in Korea, and this study attempts to investigate the clinical aspects and results of the patients who underwent surgical treatment. Material and Method: This study consist of 16 patients who underwent operations for thoracic outlet syndrome from May, 2002 to October, 2004. The surgical indications were confined to patients with: 1) symptom too severe to perform ordinary daily life because of pain, paresthesia, edema of upper extremities, 2) no improvement after proper physical therapy, 3) definite finding of compression confined by radiologic examinations (MRI, angiography, etc), and 4) no other diseases such as cervical intervertebral herniation, myositis, neurologic diseases below the brachial plexus. The surgical approaches were by transaxillary approaches in 12 cases, supraclavicular approaches in 2 cases, and infraciavicular approaches in 2 cases. Result: There were 15 males and one female with an average age of 23.9 years (range:19$\∼$39). Rib anomalies were observed in four cases (25.0$\%$), but the others had no abnormal ribs. Right lesions were found in eight cases (50.0$\%$), left lesions in five cases (31.3$\%$), and bilateral lesions in three cases (18.7$\%$). The follow-up period was 9$\∼$26 months and recurrence rate was 12.5$\%$ (2/16). Complications were one case of ulnar nerve palsy, one case of persistent pain despite radiologic improvement and three cases of wound dehiscence due to fat necrosis and hematoma. Conclusion: Although the choice of treatment in patients with TOS has been disputed, patients who have no response with proper physical therapies can benefit from the surgical treatment which may help patients to return to normal daily activity in shorter period of time.

• The Journal of Engineering Geology
• /
• v.10 no.3
• /
• pp.247-261
• /
• 2000

The geostatistical analyses for the chemical components of pH, TS, KMnO4 Demand, Cl, SO$_4$ and NO$_3$-N are carried out to understand the groundwater contamination in Pusan. The average values of each component are 7.2 for pH, 336.4mg/$\ell$ for TS, 2.3mg/$\ell$ for KMnO$_4$ Demand, 44.3mg/$\ell$ for Cl, 36.0mg/$\ell$ for SO$_4$, and 4.6mg/$\ell$ for NO$_3$-N. The ratios over the drinking standard of each component are 0.34% for pH, 2.27% for TS, 1.55% for KMnO$_4$ Demand, 1.59% for Cl, 0.57% for SO$_4$, and 3.7% for NO$_3$-N. The highest ratio of NO$_3$-N results from the municipal sewage and exhaust gas of vehicles. The isopleth maps of 6 chemical components show that the high values of groundwater contamination come from the inland of Pusan, and that some high values appear at the coastal area. The isopleth maps of Cl and SO$_4$ related with seawater intrusion also show that the high values appear only at the particular coastal area, not at the whole area. On the isopleth maps of Cl and SO$_4$, the anomalies of the concentration contours were compared with the directions of two large fault zones, the Ilkwang Fault and the Dongrae Fault. Apparently, they don't have the particular correlation. Therefore, it is concluded that the main source of groundwater contamination in Pusan is not the seawater, but the municipal sewage and other sources such as the exhaust gas of vehicles, the contaminated surface water, the waste water of factories, and the leachate of waste landfills.

• Geophysics and Geophysical Exploration
• /
• v.8 no.4
• /
• pp.262-269
• /
• 2005

Since the buried cultural relics are three-dimensional (3-D) objects in nature, 3-D survey is more preferable in archeological exploration. 3-D Ground Penetrating Radar (GPR) survey based on very dense data in principle, however, might need much higher cost and longer time of exploration than other geophysical methods commonly used for the archeological exploration, such as magnetic and electromagnetic methods. We developed a small-scale continuous data acquisition system which consists of two sets of GPR antennas and the precise positioning device tracking the moving-path of GPR antenna automatically and continuously. Since the high cost of field work may be partly attributed to establishing many profile lines, we adopted a concept of data acquisition at arbitrary locations not along the pre-established profile lines. Besides this hardware system, we also developed several software packages in order to effectively process and visualize the 3-D data obtained by the developed system and the data acquisition concept. Using the developed system, we performed 3-D GPR survey to investigate the possible historical remains of Baekje Kingdom at Buyeo city, South Korea, prior to the excavation. Owing to the newly devised system, we could obtain 3-D GPR data of this survey area having areal extent over about $17,000m^2$ within only six-hours field work. Although the GPR data were obtained at random locations not along the pre-established profile lines, we could obtain high-resolution 3-D images showing many distinctive anomalies, which could be interpreted as old agricultural lands, waterways, and artificial structures or remains. This cast: history led us to the conclusion that 3-D GPR method is very useful not only to examine a small anomalous area but also to investigate the wider region of the archeological interests.

• Journal of Yeungnam Medical Science
• /
• v.14 no.1
• /
• pp.168-174
• /
• 1997

Alphafetoprotein(AFP) is a glycoprotein synthesized by the fetus early in gestation by the yolk sac and later by the gastrointestinal tract and liver. The concentration of AFP is highest in fetal serum and amniotic fluid around 13th week, and 32nd week in maternal serum. Some conditions are associated with abnormal maternal serum AFP concentration. For examples, neural tube defects, omphalocele, renal anomalies are associated with elevated maternal serum AFP and fetal death, chromosomal trisomies are associated with low level of maternal serum AFP. So maternal serum AFP screening plays a significant role in assessing candidates for prenatal diagnosis and prenatal counselling in pregnant women. This study evaluates the normal ranges of AFP using enzyme immunoassay in normal pregnant women. We studied 500 normal pregnant women who visited the Department of Obstetrics & Gynecology, Yeungnam Medical Center, Yeungnam University during the period through January, 1993 to September, 1996. The group of the study were selected randomly at various gestational ages from 8 to 41 weeks. The results were summarized as follows: 1. The lowest level of AFP in our study group was 2.1ng/ml at 8 weeks of gestation. Thereafter serum alpha-fetoprotein concentrations rose rapidly to reach a peak value at 32nd week. 2. The mean levels of AFP in the primipara and multipara were $166.37{\pm}12.06ng/ml$, and $223.78{\pm}14.00ng/ml$, respectively, showing stastiscally significant difference between these two groups(p<0.01). 3. The mean levels of AFP between mothers who delivered male and female babies were $192.96{\pm}13.00ng/ml$, and $194.29{\pm}13.84ng/ml$, respectively, without statistically significant difference(p>0.05). 4. The normal ranges of maternal serum AFP according to each gestational week were evaluated.