• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.81-85
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• 2017

The aim of this study was to evaluate the usability of applied Low dose Computed Tomography(LDCT) protocol in examining urinary calculus using computed tomography. The subjects of this study were urological patients who visited a medical institution located in Busan from June to December 2016 and the protocol used in this study was Adaptive Statistical Iterative Reconstruction: low-dose CT with 50% Adaptive Statistical Iterative Reconstruction (ASIR). As results of quantitative analysis, the mean pixel value and standard deviation within kidney region of image(ROI)of the axial image were $26.21{\pm}7.08$ in abdomen CT pre scan and $20.03{\pm}8.16$ in low-dose CT. Also the mean pixel value and standard deviation within kidney ROI of the coronal image were $22.07{\pm}7.35$ in abdomen CT pre scan and $21.67{\pm}6.11$ in low dose CT. The results of qualitative analysis showed that four raters' mean values of observed kidney artifacts were $19.14{\pm}0.36$ when using abdomen CT protocol and $19.17{\pm}0.43$ in low-dose CT, and the mean value of resolution and contrast was $19.35{\pm}0.70$ when using abdomen CT protocol and $19.29{\pm}0.58$ in low-dose CT. Also the results of a exposure dose analysis showed that the mean values of CTDIvol and DLP in abdomen CT pre scan were 18.02 mGy and $887.51mGy{\cdot}cm$ respectively and the mean values of CTDIvol and DLP when using low-dose CT protocol were 7.412 mGy and $361.22mGy{\cdot}cm$ respectively. The resulting dose reduction rate was 58.82% and 59.29%, respectively.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.287-293
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• 2010

Purpose: This study evaluated the effect of polishing techniques on surface roughness of polymethyl methacrylate (PMMA), as well as the influence of light-cured surface glaze and subsequent brushing on surface roughness. Materials and methods: A total of 60 PMMA specimens ($10{\times}10{\times}5\;mm$) were made and then divided into 6 groups of 10 each according to the polymerization methods (under pressure or atmosphere) and the surface polishing methods (mechanical or chemical polishing) including 2 control groups. The mechanical polishing was performed with the carbide denture bur, rubber points and then pumice and lathe wheel. The chemical polishing was performed by applying a light-cured surface glaze ($Plaquit^{(R)}$; Dreve-Dentamid GmbH). Accura $2000^{(R)}$, a non-contact, non-destructive, optical 3-dimensional surface analysis system, was used to measure the surface roughness (Ra) and 3-dimensional images were acquired. The surface roughness was again measured after ultrasonic tooth brushing in order to evaluate the influence of brushing on the surface roughness. The statistical analysis was performed with Mann-Whitney test and t-test using a 95% level of confidence. Results: The chemically polished group showed a statistically lower mean surface roughness in comparison to the mechanically polished group (P = .0045) and the specimens polymerized under the atmospheric pressure presented a more significant difference (P = .0138). After brushing, all of the groups, except the mechanically polished group, presented rougher surfaces and showed no statistically significant differences between groups. Conclusion: Although the surface roughness increased after brushing, the chemical polishing technique presented an improved surface condition in comparison to the mechanical polishing technique.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.542-549
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• 2002

Purpose : The purpose of our study was to assess the usefulness of the Tl-201 SPECT for the detection of the postoperative tumor recurrence on chest wall. Methods: 28 patients including 14 with suspected recurrence of tumor in the chest wall on postoperative chest cr scan, 10 with postoperative pleural effusion which proved benign on radiologic, cytologic and laboratory findings, and 4 with chronic tuberculous empyema as control group were included. All patients underwent SPECT 30 minutes and 4 hours after intravenous injection of 111MBq of Tl-201. Tumor uptake was visually graded by two interpreters and scored as follows : no uptake:0, similar to contralateral lung: 1, higher than contralateral lung but less than heart:2 and similar to heart:3. Results : Markedly increased (grade 3 or 2) Tl-201 uptake was noted in patients with suspected recurrence of tumor in the chest wall (13/14) whereas no (8/10) or minimal (2/10) uptake along the collapsed lung in patients with postoperative benign pleural effusion. In two patients, Tl-201 SPECT revealed additional recurrent tumor mass lesions that were barely perceptible on chest cr scan. Patients with chronic tuberculous empyema showed relatively smoothly marginated increased uptake along the chest wall 4/4), but lesser in degree (grade 1 or 2), when compared to recurrent tumor uptake. Conclusion : Tl-201 lung SPECT seems to be useful to detect postoperative tumor recurrence on chest wall and to differentiate malignant from benign pleural effusion and may provide additional information to the morphologic data obtained by CT.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1232-1238
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• 2005

Purpose : Though more than 15 years have passed after introduction of Lorenzo's oil therapy in X-linked adrenoleukodystrophy(ALD), its efficacy is still fully not known. In patients who already have neurologic symptoms, most reports indicate that the neurologic disability continues to increase. We evaluated its efficacy in X-linked ALD patients. Methods : Four patients who were treated with Lorenzo's oil for at least 12 months were enrolled from 1996 to 2003. During treatment, changes of neurologic symptoms, brain magnetic resonance imaging(MRI) findings, and serum saturated very long-chain fatty acid(C26:0) were assessed. Results : Two patients with childhood cerebral ALD had progression of neurologic symptoms and MRI lesions during treatment. One asymptomatic patient developed childhood cerebral ALD after six year treatment of Lorenzo's oil. One "Addison only" patient remained neurologically intact after three years. During Lorenzo's oil therapy, serum C26:0 levels which had increased at diagnosis decreased in all four patients. Conclusion : Treatment with Lorenzo's oil did not prevent disease progression in childhood cerebral ALD patients who were already symptomatic. Long term follow up will be needed in asymptomatic ALD including "Addison only" to reveal the efficacy of Lorenzo's oil.

• The Korean Journal of Nuclear Medicine
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• v.39 no.5
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• pp.278-283
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• 2005

Purpose: In prior study, we synthesized $^{99m}Tc$-galactosylated chitosan (GC) and performed in vivo biodistribution study, showed specific targeting to hepatocyte. The aim of this study is to evaluate the labeling efficiency and cytotoxicity of modified galactosylated chitosan compounds, galactosyl methylated chitosan (GMC) and HYNIC-galactosylated chitosan (GCH). Materials and Methods: GC, GMC and GCH were synthesized and radiolabeled with $^{99m}Tc$. Then, they were incubated for 6 hours at room temperature and human serum at $37^{\circ}C$. Labeling efficiencies were determined at 15, 30 m, 1, 2, 3 and 6 h after radiolabeling. To evaluate cytotoxicity, MTT assay was performed in HeLa and HepG2 cells. Results: In comparison with them of $^{99m}Tc$-GC labeling efficiencies of $^{99m}Tc$-GMC were significantly improved (100, 97 and 89%) in acetone and 96.3, 95.8 and 75.6% in saline at 15 m, 1 and 6 h, respectively). Moreover, $^{99m}Tc$-GCH showed more improved labeling efficiencies (>95% in acetone and human serum and >90% in saline at 6 h). In MTT assay, cytotoxicity was very low and not different from that of controls. Conclusion: These results represent that these compounds are radiochemically compatible radiopharmaceuticals, can be used in hepatocyte specific imaging study and in vivo gene or drug delivery monitoring.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.715-721
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• 1999

Background:The number of old patients receiving coronary artery bypass grafting(CABG) is increasing. With the more recent advances in operative techniques, the age at which CABG is indicated has also increased. This study evaluated the risk factors associated with the hospital mortality and the morbidity following CABG in elderly patients. Material and Method: Between March 1991 and June 1998, we retrospectively reviewed 45 consecutive patients aged 65 years or older who underwent CABG. We compared the data with the results of 179 patients under the age 65 years operated during the same period. Result: Mean age was 68${\pm}$1.41 years(range 65 to 74 years). Emergency surgery was required in 4, and elective surgery in 41 patients. The mean number of distal anastomosis per patient was 3.62 ${\pm}$0.81 and mean aortic cross-cramp time was 69.84${\pm}$18.5 minutes. Thirty patients had Canadian class III or IV preoperatively, but 43 patients had class I or II postoperatively. The left ventricular ejection fraction increased significantly from 54.23${\pm}$10.62% preoperatively to 58.14${\pm}$9.88% postoperatively(p<0.05). Postoperative complication was pneumonia in 2 patients, acute renal failure in 2 patients, sternal wound infection in 1 patient, and postoperative myocardial infarction in 1 patient. There were two postoperative deaths. The causes of deaths were low output syndrome in one patient, and sepsis due to pneumonia in the other patient. The hospital mortality was higher in the elderly group(4.4 versus 2.86%) but was not statistically significant(p>0.05). Incremental risk factors for hospital deaths in the elderly were emergent operation, preoperative PTCA, postoperative use of IABP and postoperative ARF(p<0.05). The duration of hospital stay after operation was significantly longer for the elderly group than the younger group(19.27${\pm}$12.51 vs 15.55${\pm}$6.99 days; p＜ 0.05). Follow-up was complete for 34 of the hospital survivors and ranged from 1 to 73 months(mean: 23.58${\pm}$19.56 months). There was no late mortality of cardiac origin. Conclusion: Age is an important factor in selecting optimal management for elderly patients with coronary compromise, but age alone should not dictate the choice of therapy. Coronary artery bypass surgery in the elderly is associated with acceptable early mortality and excellent long-term results.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.511-516
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• 2004

Background: One of the theoretical advantages of skeletonized internal mammary artery harvesting in coronary artery bypass surgery is to minimize the interruption of the sternal blood flow inevitably accompanied by internal mammary harvesting. A study using bone scan is designed to determine the effects of internal mammary artery harvesting technique on the sternal blood flow. Material and Method: From April 2002 to March 2003, 27 patients out of 48 patients who underwent the isolated coronary bypass surgery were enrolled into the study. The enrolled patients underwent bone scan in the preoperative period and postoperative period respectively. Bilateral internal mammary artery was used in 8 patients (BIMA group) and single left internal mammary artery in 19 patients (LIMA group). The patients in LIMA group were divided into two groups: LlMA_skel group, in whom left internal mammary artery was harvested in skeletonized fashion (n=12), and LlMA_ped group, in whom left internal mammary artery was harvested in pedicled fashion (n=7). After the bone scan, the region of interest (ROI) was created on the left of the sternum and the mirror image with the same pixel numbers was placed on the right half of the sternum. The mean counts per pixel on the left side of the sternum was compared with those on the right side and expressed as left to right ratio (L/R ratio). Result: In LIMA group, the L/R ratio decreased from 94.6$\pm$4.1% to 87.9$\pm$6.9% (p=0.003) after the operation as compared to BIMA group, in which no change of the L/R ratio was observed. The changed of the L/R ratio in LlMA_skel group and LlMA_ped group were from 95.3$\pm$4.2% to 88.3$\pm$7.7% and from 93.4$\pm$3.9% to 87.4$\pm$5.8% respectively. The % changes in L/R ratio were -7.44 $\pm$7.08 in LIMA_skel group and -6.17$\pm$9.08 in LiMA_ped group, which did not reach the statistical difference. Conclusion: Ipsilateral sternal blood flow is interrupted by internal mammary artery harvesting as evidenced by the decrease in L/R ratio after left internal mammary artery harvesting irrespective of the harvesting techniques. Skeletonized harvesting did not show superiority in respect to sternal blood flow as compared to pedicled harvesting.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.547-552
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• 2004

Recently, autologous bone marrow cell transplantation (CTx) for angiogenesis and myogenesis in ischemic myocardium has been extensively investigated to improve heart functions. This study was designed to evaluate the effects of CTx with off-pump coronary artery bypass grafting (OPCAB) in patients who were not feasible for complete revascularization. Material and Method: Four male patients underwent CTx and OPCAB simultaneously. Bone marrow was aspirated from iliac bone. Mean 1.5 ${\times}$ 10$^{9}$ mononuclear cells including mean 6.7 ${\times}$ 10$^{6}$ CD34 + cells and 3.7 ${\times}$ 10$^{6}$ AC133 + cells were obtained and concentrated with 10 cc. These cells were transplanted into non-graftable ischemic myocardium after OPCAB. The heart function of all patients were evaluated using the MIBI scan, echocardiogram and MRI preoperatively. The effects of CTx was evaluated using MIBI scan and echocardiogram at 1 month postoperatively. Result: An average of 2 grafts were bypassed to left anterior descending artery territory. Other territories were transplanted with isolated mononuclear cell. All patients had uncomplicated postoperative course. After 1 month follow up, there were improvement in symptom, ejection fraction (from 49% to 55%) on echocardiogram and myocardial perfusion on MIBI scan in all patients. Conclusion: These preliminary data showed improvement of heart function and myocardial perfusion and also showed the feasibility and safety of combined therapy with OPCAB and CTx in ischemic myocardium. However, the effectiveness of CTx alone cannot be readily assessed. Further randomized, controlled studies are required to evaluate the effectiveness of CTx alone.

• Neonatal Medicine
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• v.17 no.2
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• pp.224-231
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• 2010

Purpose: Hospital readmissions have recently increased due to early hospital discharge and increased trends in breast-feeding. Neonatal hyperbilirubinemia can lead to fatal permanent neurological sequelae without appropriate management. Early detection and intervention are critical. We evaluated the clinical features, risk factors, and brain MRI findings of Korean newborns with idiopathic nonhemolytic hyperbilirubinemia to determine the optimal management policy. Methods: A retrospective review of the medical records of 79 newborns with idiopathic nonhemolytic hyperbilirubinemia was performed at the NICU of the Kyungpook National University Hospital from January 2006 to September 2009. All patients were 35 or more weeks of gestation, and their peak level of serum total bilirubin was more than 20 mg/dL. Results: The mean gestational age was $38^{+3}{\pm}1^{+4}$ weeks, and the mean age on admission was 8.8$\pm$4.0 days. The mean body weight (3,105$\pm$479 g) was decreased by 2.8$\pm$6.4 percent compared to the mean birth weight (3,174$\pm$406 g). There were no statistically significant differences for the peak serum bilirubin level or the duration and effects of phototherapy between the patients with and without risk factors, which included: breastfeeding, cephalohematoma, subdural hemorrhage, and/or ABO incompatibility. Patients were grouped according to change of body weight. Group I consisted of patients that gained weight compared to birth weight, and group II of patients that lost weight compared to birth weight. There were significant differences in the peak serum total bilirubin level between the two groups. Thirty nine patients had brain MRI evaluation; 21 patients had bilateral symmetric signal intensity increases in the globus pallidus compared to adjacent corticospinal tract and putamen on T1-weighted images. Conclusion: Bilirubin encephalopathy is preventable with early screening and proper management. Parents require instruction on feeding practices and follow-up to prevent complications from idiopathic nonhemolytic hyperbilirubinemia.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.302-308
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• 2006

Purpose: Although several neuroanatomical models of panic disorder have been proposed, little is known regarding the neurological mechanisms underlying cognitive-behavioral therapy (CBT) in patients with panic disorder. This study was performed to identify the brain structures that show changes of regnioal cerebral blood flow (rCBF) after CBT in patients with panic disorder. Materials and Methods: Seven patients who were diagnosed as panic disorder by DSM-IV were treated with CBT for 8 weeks and twelve healthy volunteers joined in this study. Serial $^{99m}Tc-ECD$ brain perfusion SPECT images were acquisited and PDSS-SR (Self-Report version of Panic Disorder Severity Scale) and ACQ (Agoraphobic Cognitive Question) scores were measured just before and after CBT in all patients. Data were analyzed using SPM2. Results: Subjective symptoms were improved, and PDSS-SR and ACQ scores were significantly reduced ($14.9{\pm}3.9\;vs.\;7.0{\pm}1.8$, p<0.05; $30.3{\pm}8.5\;vs.\;21.6{\pm}3.4$, p<0.05, respectively) after CBT in panic patients. Before CBT, a significant increase of rCBF was found in the cingulate gylus, thalamus, midbrain, both medial frontal and temporal lobes of the panic patients compared to the normal volunteers. After CBT, we observed a significant rCBF decrease in the left parahippocamus, right insula and cingulate gyrus, both frontal and temporal lobes, and a significant rCBF increase in both the occipital lobes, left insula, both frontal and left parietal lobes. Conclusion: These data suggested that CBT is effective for panic disorder and diminish the activity of the brain areas associated with fear in panic disorder.