• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.68-73
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• 2015

Purpose The purpose of this study was to evaluate image quality change by truncated region in field of view (FOV) of attenuation correction computed tomography (AC-CT) in brain PET/CT. Materials and Methods Biograph Truepoint 40 with TrueV (Siemens) was used as a scanner. $^{68}Ge$ phantom scan was performed with and without applying brain holder using brain PET/CT protocol. PET attenuation correction factor (ACF) was evaluated according to existence of pallet in FOV of AC-CT. FBP, OSEM-3D and PSF methods were applied for PET reconstruction. Parameters of iteration 4, subsets 21 and gaussian 2 mm filter were applied for iterative reconstruction methods. Window level 2900, width 6000 and level 4, 200, width 1000 were set for visual evaluation of PET AC images. Vertical profiles of 5 slices and 20 slices summation images applied gaussian 5 mm filter were produced for evaluating integral uniformity. Results Patient pallet was not covered in FOV of AC-CT when without applying brain holder because of small size of FOV. It resulted in defect of ACF sinogram by truncated region in ACF evaluation. When without applying brain holder, defect was appeared in lower part of transverse image on condition of window level 4200, width 1000 in PET AC image evaluation. With and without applying brain holder, integral uniformities of 5 slices and 20 slices summation images were 7.2%, 6.7% and 11.7%, 6.7%. Conclusion Truncated region by small FOV results in count defect in occipital lobe of brain in clinical or research studies. It is necessary to understand effect of truncated region and apply appropriate accessory for brain PET/CT.

• Childhood Kidney Diseases
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• v.16 no.1
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• pp.38-45
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• 2012

Purpose: The incidence of community-acquired urinary tract infection (UTI) due to extended-spectrum ${\beta}$-lactamase producing $Escherichia$ $coli$ (ESBL(+) $E.$ $coli$) has increased worldwide. ESBL causes resistance to various types of the newer ${\beta}$-lactam antibiotics, including the expanded spectrum cephalosporins and monobactams. We aimed to investigate the severity of UTI and associated genitourinary malformations in children with febrile UTI caused by ESBL(+) $E.$ $coli$. Methods: We retrospectively reviewed the medical records of 290 patients diagnosed as febrile UTI caused by $E.$ $coli$ between January 2008 and October 2010 at Korea University Medical center. We classified the patients into two groups with ESBL(+) and ESBL(-) $E.$ $coli$ group according to the sensitivity of urine culture. Fever duration, admission period, white blood cell (WBC) counts and C-reactive protein (CRP) in peripheral blood, the presence of hydronephrosis, cortical defects, vesicoureteral reflux (VUR) and renal scar were compared between the two groups. Results: Patients with ESBL(+) $E.$ $coli$ were 32, and those with ESBL(-) $E.$ $coli$ were 258. If we excluded those tested with a sterile urine bag, patients with ESBL(+) $E.$ $coli$ were 22, and those with ESBL(-) $E.$ $coli$ were 212. Whether the results of sterile urine bag tests were included or not, there was no significant difference in all parameters between the two groups statistically. Conclusion: Our data shows that ESBL(+) $E.$ $coli$ may not be related to the severity of UTI and associated genitourinary malformations.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.33-39
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• 2003

Purpose : Be aware of clinical possibilities on image quality by comparison of contrast-enhanced dynamic CT and MR imaging applied of MIP technique after the experimentally induced clonorchasis infection in dogs. Materials and Method : Twenty mongrel dogs prepared in zoo-laboratory were followed up with serial CT scans and MR imaging for 13 weeks after the experimental infection in liver. Two-phase helical CT was acquired in the supine position with the following scanning parameters. After the injection of contrast material, the arterial phase was initiated using a bolus-racking method. The portal phase scan was started 15 seconds after the arterial phase scan. CT protocol was determined after single level dynamic scans. MR imaging used the CP body coil and images get a 2D image using HASTE, FLASH, TSE pulse sequence. Bile duct MR imaging were obtained in three plans. Then each image was post processed by using target MIP algorithm. Two experimentation above, as a method of evaluation, one pathologist, three radiologist and five radiological technologist were analyzed visually for evaluation of following findings, enhancement of the bile duct wall, dilatation of bile duct tip, liver parenchyma, background suppression. Results : Five dogs was died of a disease after the infection, the rest one else shows the chronic dilatation of the intrahepatic bile duct with CT and MR imaging. Contrast administration of CT shows the contrast-enhanced of the bile duct walls with live parenchyma. MR imaging calculated of CNR and CR from pulse sequence for comparative evaluation and shows the pattern of the intrahepatic bile duct, dilatation of bile duct tip using MIP technique. CNR of the clonorchiasis, HASTE was $16{\pm}0.83$, TSE $7.06{\pm}3.0$, FLASH $1.19{\pm}0.2$ and CR, HASTE was 73.3%, TSE 62.3%, FLASH 6.4%. Conclusion : CT and MR imaging is very usefulness in diagnosis of dog clonorchiasis.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.283-291
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• 2009

Background: Tracheal reconstruction after extended tracheal resection still remains as a major surgical challenge because good clinical outcomes are usually correlated with limited tracheal resection. Recent investigations with a using cryopreserved trachea for the reconstruction of a trachea have been carried out to overcome this problem. In this study, we analyzed viability of tracheas, which is an important determining factor for the success of transplanting a cryopreserved trachea and the development of post-transplantation tracheal stenosis, according to three different experimental factors: 1) the warm-ischemic time, 2) the cryopreservation solution and 3) the preserving temperature, to determine a better cryopreservation protocol and a better composition of the cryopreservation solution. Material and Method: Rats tracheas were harvested for different warm-ischemic times (0 hr, 12 hrs, 24 hrs). The tracheas were treated with recombinant insulin growth factor-1 (IGF) and they were stored at three different temperatures $(4^{\circ}C,\;-80^{\circ}C,\;-196^{\circ}C)$ for two weeks. After two weeks, we thawed the stored trachea and isolated the cells of the tracheas with using type II collagenase. We cultured the cells for seven days and then we compared the cellular viability by the MTT reduction assay. Result: Though cryopreservation is required to preserve a trachea for a longer time period, the viability of the tracheas stored at $-80^{\circ}C$ and $-196^{\circ}C$ was significantly reduced compared to that of the tracheas stored at $4^{\circ}C$. The viability of the tracheas with warm-ischemic times of 12 hrs and 24 hrs was also reduced in comparison to the tracheas with a warm-ischemic time of 0 hrs. Our data showed that the warm ischemic time and the parameters of crypreservation negatively affect on trachea viability. However, a cryopresrvation solution containing IGF-1 improved the cellular viability better than the existing cryopreservation solution. For the warm ischemic time group of a 0 hr, the addition of IGF-1 improved the viability of trachea at all the preserving temperatures. Conclusion: These experiments demonstrate that the viability of cryopreserved trachea can improved by modifying the components of the crypreservation solution with the addition of IGF-1 and reducing the warm-ischemic time.

• Tuberculosis and Respiratory Diseases
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• v.39 no.5
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• pp.386-391
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• 1992

Background: Recently, bronchial provocation of the airway of atopic asthmatic subjects with inhaled allergen has been shown to produce an initial peripheral blood eosinopenia followed by an eosinophilia occurring approximately 12 to 18 hrs after the challenge. However there are few studies about the change of peripheral eosinophil count (PEC) after bronchial provocation with nonspecific stimuli such as histamine or methacholine. Interestingly our preliminary study demonstrated a notable change of PEC during bronhial provocation with inhaled histamine in some asthmatic subjects. This study was designed to reevaluate our preliminary data and to further investigate the change of PEC during as well as after bronchial provocation with inhaled histamine in bronchial asthma tics. Methods: Sixteen asthmatic subjects participated in this study. Bronchial provocation with inhaled histamine was done between 9 AM and 12 MD. Blood samplings for PEC were done with 5 minutes intervals during the procedure, and repeated at 1 hour, 2 hours, 4 hours, 8 hours, 24 hours, and 48 hours after the procedure. Results: The results were as follows; 1) The patients were divided into two groups characterized by each pattern in the change of PEC during the procedure. A group (11 of sixten, group I) showed an increasing pattern of PEC and another group (5 of sixteen, group II) showed a decreasing pattern of PEC during the procedure. 2) Group I demonstrated a tendency to maintain continuously higher level of PEC than the baseline value until 48 hours after the procedure. 3) Group II demonstrated a tendency to maintain continuously lower level of PEC than the baseline value until 48 hours after the procedure. 4) There were no significant differences in their clinical parameters including baseline eosinophil count, baseline $FEV_1$, $PC_{20}$ of histamine, and serum IgE level between group I and group II. Conclusion: Our results suggest that the change of PEC produced by inhaled histamine in asthmatic subjects is much different from that produced by inhaled allergen, and that each patient may have their individual characteristics in the change of PEC in response to bronchial provocation with inhaled histamine. Alternatively these findings suggest that eosinophils may be partially involved in the early asthmatic reaction.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.294-300
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• 2010

Purpose: The template-guided implant surgery offers several advantages over the traditional approach. The purpose of this study was to evaluate the accuracy of coordinate synchronization procedure with 5-axis milling machine for surgical template fabrication by means of reverse engineering through universal CAD software. Materials and methods: The study was performed on ten edentulous models with imbedded gutta percha stoppings which were hidden under silicon gingival form. The platform for synchordination was formed on the bottom side of models and these casts were imaged in Cone beam CT. Vectors of stoppings were extracted and transferred to those of planned implant on virtual planning software. Depth of milling process was set to the level of one half of stoppings and the coordinate of the data was synchronized to the model image. Synchronization of milling coordinate was done by the conversion process for the platform for the synchordination located on the bottom of the model. The models were fixed on the synchordination plate of 5-axis milling machine and drilling was done as the planned vector and depth based on the synchronized data with twist drill of the same diameter as GP stopping. For the 3D rendering and image merging, the impression tray was set on the conbeam CT and pre- and post- CT acquiring was done with the model fixed on the impression body. The accuracy analysis was done with Solidworks (Dassault systems, Concord, USA) by measuring vector of stopping’s top and bottom centers of experimental model through merging and reverse engineering the planned and post-drilling CT image. Correlations among the parameters were tested by means of Pearson correlation coefficient and calculated with SPSS (release 14.0, SPSS Inc. Chicago, USA) ($\alpha$ = 0.05). Results: Due to the declination, GP remnant on upper half of stoppings was observed for every drilled bores. The deviation between planned image and drilled bore that was reverse engineered was 0.31 (0.15 - 0.42) mm at the entrance, 0.36 (0.24 - 0.51) mm at the apex, and angular deviation was 1.62 (0.54 - 2.27)$^{\circ}$. There was positive correlation between the deviation at the entrance and that at the apex (Pearson Correlation Coefficient = 0.904, P = .013). Conclusion: The coordinate synchronization 5-axis milling procedure has adequate accuracy for the production of the guided surgical template.

• Journal of Chest Surgery
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• v.35 no.1
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• pp.1-10
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• 2002

Background: Despite the relatively high mortality rates in the chronic heart failure model induced by coronary artery ligation are relatively high, this model has been a subject of continuos research because of its clinical correlation. Chronic heart failure model of large-sized animals is very useful to analyse mechanical or biological effects on circulatory system which is difficult in small-sized animals. The purpose of this study is to establish the heart failure model by coronary artery ligation in sheep. Material and Method: Among 9 Corridale sheep, the homonymous artery and the diagonal branch were ligated simultaneously in 2 sheep and remaining 7 sheep were assigned to successive ligation of both arteries at an interval of 1 hour. Both coronary arteries were ligated from the point 40% proximal to the apex of the heart. Hemodynamic and echocardiographic parameters were analyzed before the ligation of the coronary artery, after the ligation of the homonymous artery, and after additional ligation of the diagonal branch. The experimental animals were sacrificed after 2 or 3 months of growth and histopathologic studies were performed Result: Immediate postoperative death occurred in the 2 sheep that had received simultaneous ligation of the homonymous artery and diagonal branch. On the other hand, all the 7 sheep that were lifated in succession were survived up to 3 months. Arterial pressure was sifnificantly decreased immediately after ligation of the homonymous artery(p<0.05), and the cardiac output was decreased and pulmonary capillary wedge pressure was increased after further ligation of the diagonal branch(p<0.05). Central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, left ventricular end-diastolic dimension and end-systolic dimension were markedly increased 3 months after ligation of coronary arteries. Anteroseptal akinesia or dyskinesia was developed after the ligation of coronary arteries. Histopathologic study revealed we]1-demarcated ischemic area of fibrosis. Conclusion: Using methods of successive ligation of the homonymous artery and diagonal branch, chronic heart failure model could be reliably established in sheep.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1275-1281
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• 2006

Purpose : Cerebral edema in meningitis is a potentially complication. Hypertonic saline of various concentrations are frequently used to treat cerebral edemas in meningitis. We analyzed the safety and efficacy of osmotic therapy in cerebral edema by comparison of various hypertonic saline concentrations and mannitol. Methods : The medical records of 42 patients, who were followed up in the Department of Pediatrics, Busan Medical Center, from Jan. 2002 to Oct. 2005, were analyzed retrospectively. We measured intracranial pressure, mean flow velocity, and various laboratory parameters. Results : In cerebral edema developed in meningitis, intracranial pressure and symptoms were improved in treatment of hypertonic saline and mannitol. Serial bolus infusion of 3 percent hypertonic saline resulted in the best outcome. There was not a statistically considerable difference on the mean values of the intracranial pressure gap. On transcranial doppler, mean flow velocity was increased and pulsatilty index was decreased. Laboratory findings (osmolarity, Na, Cl, pH, lactic acid, Ca) were diffenent during the treatment period as opposed to K, Hb, bicarbonate, base excess. There was not a specific form of hypertonic saline used in meningitis treatment with cerebral edema. Conclusion : The therapy for cerebral edema in meningitis remains largely empirical. Serial bolus infusion of 3 percent hypertonic saline is better than other hypertonic salines. Various concentrations and different infusion methods of hypertonic saline statistically does not influence the result of treatment. More research aimed at improving cerebral edema treatment is needed to identify new, effective forms of treatment.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.475-481
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• 2006

Purpose : As the prevalence of childhood obesity is increasing, hypertension, hyperlipidemia, insulin resistance and diabetes mellitus have become problems. High homocysteine levels and low vitamin $B_{12}$ supplementation are acknowledged to have a role in coronary artery disease, but there are few studies on homocysteine, insulin and vitamin $B_{12}$ levels in obese children. We aimed to study whether homocysteine, insulin, vitamin $B_{12}$, folic acid levels could have any difference and relation in obese children. Methods : The disease group consisted of 27 children from 8 to 11 years old, whose obesity index was over 130. The control group consisted of 30 healthy children of the same age group. Obesity index and body mass index were calculated by height and body weight of the children, and their systolic and diastolic blood pressures at resting state were checked. Total cholesterol, triglyceride, homocysteine, insulin, vitamin $B_{12}$, folic acid levels were studied after 10 hours of fasting. Intracellular fluid, extracellular fluid, protein, mineral, muscle mass, lean body fat, fat mass and fat percentages were checked by bioelectrical impedance. Results : Homocysteine levels were higher in obese children($8.1{\pm}2.1{\mu}mol/mL$ vs. $4.9{\pm}1.0{\mu}mol/mL$). Insulin levels were also higher in obese children($26.8{\pm}11.2{\mu}IU/mL$ vs. $12.5{\pm}5.24{\mu}IUl/mL$). Vitamin $B_{12}$ was lower in obese children($798.6{\pm}174.3pg/mL$ vs. $967.8{\pm}405.0pg/mL$). But there was not a difference in the folic acid levels between the two groups. In obese children, systolic blood pressure (r=0.535), triglyceride(r=0.517), total cholesterol(r=0.408), folic acid(r=0.408), vitamin $B_{12}$(r=0.338) and abdomoanl fat %(r=0.306) had a positive correlation. Conclusion : We found definite differences of insulin, homocysteine, and vitamin $B_{12}$ plasma levels in obese children, but we need more study to use those parameters as risk factors of metabolic syndrome in pediatric obese patients.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.48-54
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• 2005

Purpose : The pathologic mechanisms of central nervous system(CNS) injuries in human meningitis are not yet completely understood. Recent studies indicate that the host inflammatory responses are as important in brain damage as the infecting organisms and toxins. There have been some reports on the relationship of nitric oxide(NO), macrophage inflammatory protein-$1{\alpha}$(MIP-$1{\alpha}$), and lactoferrin in bacterial meningitis, but few reports in aseptic meningitis. Thus, we investigated the concentrations of NO, MIP-$1{\alpha}$ and lactoferrin in cerebrospinal fluid(CSF) and serum of patients with aseptic meningitis and control subjects and evaluated their relationship with other parameters of meningitis. Methods : CSF and blood were obtained from 25 subjects with aseptic meningitis and 15 control subjects. After centrifugation, supernatants were stored at $-70^{\circ}C$ and we assayed the concentrations of NO, MIP-$1{\alpha}$ and lactoferrin with the ELISA method. There were no patients with neurologic sequelae after being recovered from aseptic meningitis. Results : Concentrations of CSF and serum NO, MIP-$1{\alpha}$ were not increased in aseptic meningitis subjects compared to control subjects. Concentration of CSF lactoferrin was significantly elevated in patients with aseptic meningitis and concentration of serum lactoferrin was significantly decreased in patients with aseptic meningitis compared with those in control subjects(P<0.05). CSF lactoferrin level was positively correlated with CSF WBC counts($r_s=0.449$, P=0.007), especially with neutrophil counts($r_s=0.574$, P<0.001) and CSF protein level($r_s=0.508$, P=0.002). Conclusion : Lactoferrin plays an important role in aseptic meningitis and may be released from neutrophils recruited from blood to the CSF through breakdown of blood-brain barrier. NO and MIP-$1{\alpha}$ may not be important factors in the pathogenesis of aseptic meningitis without neurologic sequelae.