• Progress in Medical Physics
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• v.20 no.2
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• pp.80-87
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• 2009

Phase transformation, superelastic characteristics and variation of surface residual stress were studied for Nitinol shape memory alloy through application of UNSM technology, and life extension methods of stent were also studied by using elastic resilience and corrosion resistance. Nitinol wire of ${\phi}1.778$ mm showed similar surface roughness before and after UNSM treatment, but drawing traces and micro defects were all removed by UNSM treatment. It also changed the surface residual stress from tensile to compressive values, and XRD result showed less intensive austenite peak and clear martensite and additional R-phase peaks after UNSM treatment. Fatigue resistance could be greatly improved through removal of surface defects and rearrangement of surface residual stress from tensile to compressive state, and development of surface modification system to improve not only bio-compatability but also resistance to corrosion and wear will make it possible to develop vascular stent which can be used for circulating system diseases which run first cause of death of recent Koreans.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.604-610
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• 2006

Background: Recent improvements in interventional procedure and medical therapy for congestive heart failure result in an increase of number of patients with ischemic cardiomyopathy considered for coronary artery bypass grafting. We retrospectively review the results of CABG in these patients with decreased LV function to know the early and mid-term follow-up results. Material and Method: Between January 2001 and June 2005, 1,143 patients underwent coronary artery bypass grafting and 144 of these patients had preoperative left ventricular function of equal to or less than 35% ${(LVEF{\leq}\;35%)}$. There were off-pump coronary artery bypass grafting (OPCAB) in 66 cases (45.8%), on-pump beating heart coronary artery bypass grafting in 34 cases (23.6%) and conventional coronary artery bypass grafting in 44 cases (30.6%). The combined operations including mitral annuloplasty were 48 cases in thirty five patients (24.3%). Result: The mean number of dstal anastomosis were $3.5{\pm}1.3$. The median postoperative duration of stay in intensive care unit and hospital was 2 days and 8 days, respectively. There were 6 early death (4.2%) and causes of deaths were ventricular tachycardia in 5 patients, small bowel infarction in one patient. Mean follow-up time was $21{\pm}14$ months $(4{\sim}54\;months)$. The 1-year was $95{\pm}2%$ and 3-year survival rate was $83{\pm}7%$, the 1-year and 3-year cardiac event-free survival were ${88{\pm}3%\;and\;69{\pm}7%}$, respectively. Conclusion: Based on satisfactory early and mid-term results in our study, CABG should be carried out as actively as possible in patients with ischemic cardiomyopathy. Postoperative aggressive management for ventricular arrhythmia would be helpful for better results.

• Journal of Gastric Cancer
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• v.8 no.3
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• pp.160-165
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• 2008

Purpose: With the introduction of H. pylori eradication and proton pump inhibitor, the operative treatments for the acute or chronic complications of peptic ulcer, such as perforation, bleeding and stricture, have decreased. Also owing to the development of non-operative treatment such as interventional endoscopic treatment, the surgical approach to the acute complications, like perforation and bleeding, has diminished. The non-operative treatments for the stricture and obstruction of chronic peptic ulcer in part related to discontinuation of medication have not been satisfactory. We analyzed the clinical outcomes of the patients who underwent operative treatment for outlet obstruction with peptic ulcer. Materials of Methods: From January 1994 to December 2007, we reviewed 31 patients who had been operated on at the National Medical Center for peptic ulcer obstruction. We excluded the cases of adhesive obstructions that were caused by a former ulcer operation and also the cases of obstructions found during emergency operations for treating perforation and bleeding. We classified the surgical treatment group into the bypass operation group and the surgical resection group. We evaluated the effects of the operations by the Visick score. The recurrences were confirmed only by the endoscopic observation of peptic ulcer. Results: The number of patients in the bypass operation group was 6 (19.4%) and that of resection group was 25 (80.6%). The mean age was 57.5 (25~81) years. The number of male patients was 29 (93.5%) and the number of females was 2 (6.5%). The mean symptom duration was 29.6 months. There were 19 smokers (61.3%), 6 NSAID users (19.4%) and 7 H. pylori positive patients (22.6%). Two patients underwent endoscopic balloon dilatation with no success. The locations of lesion were the stomach, the duodenum and both in 9, 20 and 2 cases, respectively. There were operative complications in 13 cases (41.9%), recurrent ulcers in 2 cases (6.5%), and reoperations in 4 cases. The mean Visick score was 1.8 (1~4). There were no statistically significant clinicopathologic differences between the bypass operation group and the resection group. The two groups had 1 case each of recurrence. Although the bypass group had a greater complication rate (83.3%) than the resection group (32%), this was not statistically meaningful (P=0.175). The mean Visick score was 3.0 in the bypass group and 1.6 in the resection group, so the resection group was better (P=0.001). Conclusion: For a case of chronic peptic ulcer with outlet obstruction, even though it has been reported that endoscopic balloon dilatation worked well, surgery is still regarded as an important treatment. If you consider the patients' satisfaction and the difficulty of diagnosing malignant ulcers, surgical resection should be recommended more often than a bypass operation.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.319-336
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• 2020

The purpose of this study was to compare the outcomes of two interventional methods, overlapping drug-eluting stents (DES) and long DES, for long-term clinical outcomes in patients with acute myocardial infarction (AMI). A total of 438 patients with AMI (65.9±11.0 years, 306 males) from June 2008 to March 2019 who had diffuse long coronary artery lesion, more than 30mm were divided into two groups; group I (overlapped DES group; n=140) and group II (long DES group; n=298). We compared the incidences of major adverse cardiac events [MACEs; cardiac death, myocardial infaction (MI), target lesion revascularization (TLR) and stent thrombosis (ST)] during 12 months between the two groups. Everolimus-eluting stent was more commonly used in group II than in group I (28.1% vs. 51.8% p<0.001). Mean lesion diameter was slightly longer in group II (3.1±0.3mm vs. 3.2±0.3mm, p=0.042), and prevalence of ACC/AHA lesion type C was higher in group I (41.7% vs. 25.4%, p<0.001). Incidences of MACEs during 12 months were higher in group I than group II (18.5% vs. 14.4%, p=0.034). The rates of cardiac death (2.1% vs. 4.4%, p=0.667), MI (5.0% vs. 2.7%, p=0.260) and stent thrombosis rate (0.7% vs. 1.7%, p=0.669) were similar between the two groups. However, TLR rate was higher in group I (10.7% vs. 5.6%, p=0.041). In multivariate logistic regression analysis, presence of diabetes mellitus [Hazard ratio (HR) 2.383, 95% confidence interval (CI) 1.332-4.260, p=0.003] and use of paclitaxel-eluting stent (HR) 2.367, 95% CI 1.371-4.086, p=0.002) were independent predictors of 12-month MACEs, without significant differences in prevalence between the two groups. In AMI patients with diffuse long lesion, TLR rate was higher in the overlapped DES group during 12-month follow-up. Presence of diabetes and use of paclitaxel-eluting stent were independent predictors of MACEs.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.67-70
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• 2013

Purpose: Surge in patients with hepatocellular carcinoma, hepatic artery chemical embolization is one of the effective interventional procedures. The PET/CT examination plays an important role in determining the presence of residual cancer cells and metastasis, and prognosis after embolization. The other hand, the hepatic artery chemical embolization of embolic material used lipiodol produced artifacts in the PET/CT examination, and these artifacts results in quantitative evaluation influence. This study, the radioactivity density and the percentage error was evaluated by the extent of the impact of lipiodol in the image of PET/CT. Materials and Methods: 1994 NEMA Phantom was acquired for 2 minutes and 30 seconds per bed after the Teflon, water and lipiodol filled, and these three inserts into the enough to mix the rest behind radioactive injection with $20{\pm}10MBq$. Phantom reconfigure with the iterative reconstruction method the number of iterations for two times by law, a subset of 20 errors. We set up region of interest at each area of the Teflon, water, lipiodol, insert artifact occurs between regions, and background and it was calculated and compared by the radioactivity density(kBq/ml) and the% Difference. Results: Radioactivity density of the each region of interest area with the teflon, water, lipiodol, insert artifact occurs between regions, background activity was $0.09{\pm}0.04$, $0.40{\pm}0.17$, $1.55{\pm}0.75$, $2.5{\pm}1.09$, $2.65{\pm}1.16 kBq/ml$ (P <0.05) and it was statistically significant results. Percentage error of lipiodol in each area was 118%, compared to the water compared with the background activity 52%, compared with a teflon was 180% of the difference. Conclusion: We found that the error due to under the influence of the attenuation correction when PET/CT scans after lipiodol injection performed, and the radioactivity density is higher than compared to other implants, lower than background. Applying the nonattenuation correction images, and after hepatic artery chemical embolization who underwent PET/CT imaging so that the test should be take the consideration to the extent of the impact of lipiodol be.

• Tuberculosis and Respiratory Diseases
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• v.64 no.4
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• pp.272-277
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• 2008

Background: The efficacy of the use of the interventional bronchoscope for palliation of patients with central airway obstruction has been established. In the palliative setting to alleviate central airway obstruction, the use of laser resection, electrocautery, argon plasma coagulation, photodynamic therapy and cryotherapy can provide relief of an airway obstruction. Cryotherapy is the therapeutic application of extreme cold for the local destruction of living tissue. Recently, this technique has been used for endoscopic management of central airway obstructions in Korea. We report the role and complications of the use of cryotherapy for airway obstructions in patients with advanced lung cancer. Methods: We used a flexible cryoprobe for cryotherapy using nitrous oxide as a cryogen. The cryoprobe was applied through the working channel of a flexible fiberoptic bronchoscope. The temperature of the tip was approximately $-89^{\circ}C$, and the icing time was 5~20 seconds. Results: Four patients with a central airway obstruction from advanced lung cancer were treated with cryotherapy. Three of the four patients were treated successfully and the airway obstruction was improved after the cryotherapy procedure. Dyspnea, hypoxia and atelectais were improved in three cases. Two patients experienced complications- one patient experienced pneumomediastinum and the other patient experienced massive hemoptysis during the cryotherapy procedure. However, these complications resolved and did not influence mortality. Conclusion: This technique is effective and relatively safe for palliation of inoperable advanced lung cancer with a central airway obstruction.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.242-251
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• 2011

A curriculum of study demands a change as period of time and society evolve. Therefore, at this point where changes are required, this study is to analyze and evaluate the curriculums which will enhance and improve current studies as a preceding stage. The research was based on the survey by groups of education experts and 19 universities with current curriculum of study in radiologic science, and their references. The study was focused on the scope of work by radiologic technologist, change of college systems, academic research about radiologic science, and the improvement and the future of radiologic science field in perspective to globalization and the digital era. In terms of work scope, angiography and interventional radiology at 6 to 8 schools, fluoroscopy at 4 schools, ultrasound and practices at 6 schools, magnetic resonance image at 2 schools were found to be unestablished. The basic medical subjects, humuan physiology, human anatomy and practices, medical terminology courses were set up at most schools; however, pathology at 5 schools, image anatomy at 6 schools, clinical medicine at 11 schools were yet opened. Among the basic science and engineering subjects, general biology and its practices at 11 schools, general physics and its practices at 14 schools, and general chemistry and its practices at 8 schools were established which is about a half from a total number of schools. Only 4-5 schools established digital subjects such as, health computer, computer programming, PACS which are the basic major subjects. In order to provide academic improvement in radiologic science, digitalized education and globalization, and basis for future-oriented education for the field of radiologic science, including expanded scope of work, it is acknowledged that curriculums that are opened and run at each school need to be standardized. Therefore, the need for introduction of certificate for the radiologic science education courses are suggested.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.2
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• pp.54-58
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• 2010

Purpose: In patients with chronic cervical pain, the facet joint is the source of the majority. Due to the difficulty of identifying the exact location of the joint that causes these symptoms, the possibility of complications and the placebo effect brings clinical application into question. In this study, we assessed the prevalence of patients with chronic cervical pain and report the diagnostic and therapeutic usefulness of ultrasonography - guided facet joint block therapy. Materials and Methods: Patients with nonspecific chronic cervical pain for more than 6 months were selected. Patients with disc herniation, sciatica-related pain were excluded from the study and 160 patients who failed in conservative treatment (physical therapy, chiropractic therapy, medication) were included in the study. Diagnostic Ultrasonography-guided facet joint block was performed with 1% lidocaine, and after two weeks, Bupivacaine 0.25% was used in patients who tested positive for lidocaine. Patients with more than 75% pain reduction during movement after facet joint block were considered positive. Results: Among the 160 patients with chronic cervical pain, 96 patients(60%) had a positive reaction after facet block using lidocaine. Among the 64 patients with a negative reaction to lidocaine, 48 patients(75%) had a positive reaction to bupivacaine. There were 48 false positive patients(50%) who showed a positive reaction to lidocaine but a negative reaction to bupivacaine. The mean VAS of the total 160 patients before blocks was 8.5, after 2 weeks follow up it decreased to 2.7 (p = 0.001) and after 4weeks 3.6 (p = 0.001). The 8 patients as an initial improvement of symptoms are not satisfied with the procedure and the 3 patients had been worsened during observation, were showed pain relief after additional ultrasonography-guided facet joint block at 4th week. Conclusion: A single ultrasonography-guided block to chronic cervical pain patients has relatively low diagnostic value since high false positive rate. The twice facet joint blocks is thought to be a useful method for interventional pain management of patients with chronic cervical pain.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.629-638
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• 1997

Background : Surgical intervention is known as the principle management for hemoptysis of significant amount. But surgical procedure is applicable to only small number of patients because of increased mortality in emergency surgery and various functional and structural problems after lung resection. Bronchial artery embolization(BAE) has been used as an alternative interventional technique for immediate control of patients with increased risk for surgery due to recurrent or massive hemoptysis. BAE also has limitations such as recurrent bleeding after procedure and its role for the application to small amount of hemoptysis is still not established. Method : To evaluate immediate and long term effectiveness of BAE, we analysed 65 patients with hemoptysis according to therapeutic modalities they received ; BAE versus conservative management. Results : The success rate for immediate control of hemoptysis was significantly higher in BAE group with 43 cases(100%) among 43 cases compared with 17 cases(77%) among 22 cases in conservative group (p < 0.001). The disease control duration was $19.5{\pm}8.06$ months in BAE group and $18.8{\pm}6.06$ months in conservative group(p > 0.05). The therapeutic response in BAE group was 82%(36/43 cases) and 95%(21/22 cases) in conservative group (p > 0.05). According to the amount of hemoptysis, the therapeutic response were seen in 91%(29/32 cases) in less than 100ml and 85%(28/33 cases) in 100~400ml (p > 0.05). According to the manifestation of hemoptysis, the therapeutic response in groups of recurrent and nonrecurent were 87%(20/23 cases) and 88%(37/42 cases)(p > 0.05). Conclusion : The difference of therapeutic response between BAE and conservative group in patients with small amounts of hemoptysis was not found except for immediate control of hemoptysis.

• The Journal of Korean Academy of Sensory Integration
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• v.17 no.3
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• pp.26-45
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• 2019

Objective : The purpose of this study is to develop educational goals, training content, and training methods for the intervention course of the Korean Academy of Sensory Integration (KASI) and to conduct competency-based intervention courses based on the competency model for sensory integration intervention. Methods : This study was conducted on work therapists who participated in the 2019 intervention course of KASI. In the first phase, educational needs were analyzed to set goals for the interventional course. In the second phase, a meeting of researchers drafted the intervention course education program and the methods of education, and the intervention course was conducted. In the third phase, the changes in educational satisfaction and performance level pre- and post-intervention course for each competency index were investigated. Results : The educational goals of "learning and applying the clinical reasoning process of sensory integration intervention" and "intervention by applying the principle of sensory integration intervention" were set after reflecting on the results of the analysis of the educational requirements. The length of the competency-based intervention course was 42 hours. The average education satisfaction level of participants in the arbitration process was 4.48±0.73, and the average education satisfaction level of the supervisor was 3.92±0.71. In both groups, the most satisfying curriculums were the data-driven decision-making process and the intervention goal-setting lecture. But the satisfaction level of was the lowest. Before and after the intervention course, there were significant changes in the performance of the two behavioral indicators of the analytic skills in the expertise competency cluster of the competency model. Conclusion : This study is meaningful in that it conducted a survey of educational needs, the development and implementation of an educational curriculum, and an education satisfaction survey through systematic courses necessary for education development.