• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5682-5688
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• 2013

The purpose of this study is to maximize diagnositc usefulness with increasing signal to noise ratio(SNR) and contrast to noise ratio(CNR) by using a 1mmol/mL gadolinium contrast agent. From January 2012 to June 2013 fourty-seven patients were underwent the MRI scanning to investigate the contrast difference in gadolinium content. Twenty of the patients were injencted the commercial contrast agent containing 0.5mmol/mL gadolinium and the rest of them were injected the new contrast agent containing 1mmol/mL gadolinium called gadobutrol. We measured and evaluated each SNR and CNR of the hip joint space, iliopsoas muscle and femoral head. As a result, using the 1mmol/mL gadolinium contrast agent had the higher SNR results than using the 0.5mmol/mL agent(27% in the hip joint, 30.01% in the femoral head). Also CNR using the 1mmol/mL gadolinium agent was proved to be higher than that of using 0.5mmol/mL agent(28.31% in the ilopsoas muscle and 26.74% in the femoral head). Therefore, the contrast agent containing more gadolinium like 1mmol/mL used in this study is more effective to shorten T1 relaxation time, so it increases the signal intensity and CNR and furthermore maximizes diagnostic value. This study reports the usefulness of the 1mmol/mL contrast agent in the contrast-enhanced magnetic resonance hip arthrography for the first. Therefore, it can be considered to have an meaningful academic value as showing the method for increasing the diagnostic usefulness by using the 1mmol/mL contrast agent.

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.401-410
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• 2003

This study investigates the biomechanical efficacies of various cement augmentation techniques with or without pressurization for varying degrees of osteoporotic femur. For this study, a biomechanical analysis using a finite element method (FEM) was undertaken to evaluate surgical procedures, Simulated models include the non-cemented(i.e., hip screw only, Type I), the cement-augmented(Type II), and the cemented augmented with pressurization(Type III) models. To simulate the fracture plane and other interfacial regions, 3-D contact elements were used with appropriate friction coefficients. Material properties of the cancellous bone were varied to accommodate varying degrees of osteoporosis(Singh indices, II∼V). For each model. the following items were analyzed to investigate the effect surgical procedures in relation to osteoporosis of varying degrees : (a) von Mises stress distribution within the femoral head in terms of volumetric percentages. (b) Peak von Mises stress(PVMS) within the femoral head and the surgical constructs. (c) Maximum von Mises strain(MVMS) within the femoral head, (d) micromotions at the fracture plane and at the interfacial region between surgical construct and surrounding bone. Type III showed the lowest PVMS and MVMS at the cancellous bone near the bone-construct interface regardless of bone densities. an indication of its least likelihood of construct loosening due to failure of the host bone. Particularly, its efficacy was more prominent when the bone density level was low. Micromotions at the interfacial surgical construct was lowest in Type III. followed by Type I and Type II. They were about 15-20% of other types. which suggested that pressurization was most effective in limiting the interfacial motion. Our results demonstrated the cement augmentation with hip screw could be more effective when used with pressurization technique for the treatment of intertrochanteric fractures. For patients with low bone density. its effectiveness can be more pronounced in limiting construct loosening and promoting bone union.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.156-160
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• 2002

Purpose : To evaluate the results and usefulness of meniscal repair using meniscal arrows with ACL reconstruction. Material and Methods : Among cases of the simultaneous meniscal arrow fixation and ACL recontruction performed between May, 1997 and September, 2000, 17 cases could be evaluated. The average follow-up were 18.5 months. Twelve cases were medial meniscus, 5 cases, lateral meniscus. All cases were longitudinal tear. Meniscal tear were seen at red-red zone in 13 cases, red-white zone in 5 cases. The results were analyzed by pain, joint line tenderness, locking, McMurray test, the Marshall knee scoring scale and complications. Results : Postoperatively two patients had mild joint line tenderness without pain on joint motion or weight bearing. No patient had locking or positive McMurray test. At last follow-up, 15 cases $(88\%)$ were 'excellent' or 'good' according to the Marshall knee score scale. There were two complications which are soft tissue irritation sign on active knee motion and a femoral chondral injury due to protruded T-shaped head of meniscus arrow. Conclusion : Meniscus arrow can be one of the options in repairing the associated meniscus tear, especially the posterior horn of medial meniscus, during ACL reconstruction. However, surgeons using meniscus arrow should be aware of its potential complications such as pain due to soft tissue irritation and chondral damage of the femoral condyle.

• Progress in Medical Physics
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• v.21 no.2
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• pp.183-191
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• 2010

In this study, the patient with localized prostate cancer who had previously been treated at Ajou University Hospital was randomly selected since March, 2009. we performed IMRT and 2RA plans and the same dose objectives were used for CTVs, PTVs, rectum, bladder, and femoral head of the respective plans. Arc optimizations and dose calculations were performed using Eclipse versions 8.6. In this paper, we evaluated the performance of IMRT and RA plans to investigate the clinical effect of RA for prostate cancer case. In our comparison of treatment techniques, RA was found to be superior to IMRT being better dose conformity of target volume. As for the rectum and bladder, RA was better than IMRT at decreasing the volume irradiated. RA has the ability to avoid critical organs selectively through applied same dose constraints while maximally treating the target dose. Therefore, this result suggests that there should be less rectal toxicity with RA compared with IMRT, with no compromise in tumor margin. These findings, which show more favorable rectal, bladder, and femoral head DVHs with RA, imply that should not result in excess risk of toxicity when this technique is used. Many experiences with RA have shown not only dosimetric advantage, but also improved clinical toxicity when comparing with IMRT. The main drawbacks of RA are the more complex and time-consuming treatment planning process and the need for more exact physics quality assurance (QA).

• Journal of Life Science
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• v.18 no.4
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• pp.427-434
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• 2008

Osteonecrosis of the femoral head (ONFH) is a multifactorial disease and certain individuals are more at risk or may be predisposed to it. An altered lipid metabolism is one of the major risk factors for osteonecrosis, especially corticosteroid therapy and alcoholism. 3-hydroxy-3-methylglutaryl coenzyme A. (HMG-CoA) reductase inhibitors, stalin used as lipid-clearing agent, have been known to decrease the risk of osteonecrosis in patients receiving steroids and affect coagulation and fibrinolysis. Therefore we evaluated the association of HMG-CoA reductase gene polymorphisms and haplotypes between osteonecrosis patients and normal controls. We directly sequenced the HMG-CoA reductase gene in 24 Korean individuals, and identified five sequence variants. Four SNPs (-6933C>T, -6045T>G, +12673G>A, and +18128C>T) were selected and genotyped in 349 male ONFH patients and 300 male control subjects. The genotypes, allele frequencies, and haplotypes of the polymorphisms in the total patients as well as in the subgroup by etiology were not significantly different from those in the control group. In addition, no significant differences between each genotype of the polymorphisms and plasma lipid level could be found in the control group. These results suggest that the polymorphisms and haplotypes of HMG-CoA reductase gene are unlikely to be associated with a susceptibility to ONFH.

• Journal of Veterinary Clinics
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• v.30 no.1
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• pp.49-52
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• 2013

A wild black-crowned night heron (Nycticorax nycticorax) with dehydration and a non-weight bearing lameness of the left leg was rescued. On physical examination, the left knee was displaced laterally at almost a $90^{\circ}$ angle with firm swelling and crepitus in the area of the coxofemoral joint. Radiographs confirmed cranio-dorsal coxofemoral luxation. A closed reduction attempt failed. The coxofemoral joint luxation was reduced surgically by placement of the femoral neck next to the pelvis with a suture. Ten days after surgery, radiographs and computed tomography showed the femoral neck and head were positioned well within the acetabulum. At 20 days, the bird was using the affected limb normally, and could hunt and forage for food in a rehabilitation housing unit with a small pond. The bird was successfully released into the wild. The placement of the femoral neck adjacent to the pelvis with a suture can be successfully performed for cases of avian coxofemoral joint luxation. Furthermore, this procedure can provide sufficient stabilization of the coxofemoral joint and acceptable limb function.

• Korean Journal of Head & Neck Oncology
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• v.12 no.1
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• pp.32-42
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• 1996

This study was desinged to evaluate the effect of radioactive iodine-131 therapy in differentiated thyroid carcinoma treated at the Presbyterian Medical Center, Chonju during the 20-year period from 1975 to 1994. The authors reviewed 246 patients who received radioactive iodine-131. An analysis of the therapeutic response and survival rates of the 246 patients has been carried out. The male to female ratio was 1 : 3.6. The peak incidence was in the 4th and 6th decades. The histologic findings in the 246 patients were papillary adenocarcinoma in 200 cases, follicular adenocarcinoma in 29 cases, mixed type in 14 cases, and others in 3 cases. Combined treatment modalities of 246 patients consisted of sugery and radioiodine in 222 cases, surgery with radioiodine and external irradiation in 11 cases, and surgery with radioiodine, external irradiation and chemotherapy in 5 cases. 42 of the 246 cases showed recurrence and the commonest type of combined treatment for recurrent case was surgery followed by radioiodine-131. The highest accumulated total dosage of radioiodine-131 was 480mCi in that case femoral metastasis was noticed. The most common locoregional metastatic site was ipsilateral cervical node, and neighbouring muscle, vessel, trachea, recurrent layngeal nerve, in order of frequency. The determinate 10-year survival rate was 91.8% in the group receiving surgery followed by radioiodine-13l and 71.4% in patients receiving surgery, radioiodine-13l with XRT. The determinate 10-year survival rate was better for patients under 40 years of age who received radioiodine as compared to patients over 40 year of age(85.7% vs. 33.3%). The most usual primary therapeutic dosage in the group of cervical lesion was 90$\sim$120mCi after surgery.

• Journal of Korean Neurosurgical Society
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• v.61 no.4
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• pp.509-515
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• 2018

Objective : In Asians, kneeling and squatting are the postures that are most often induce common peroneal neuropathy. However, we could not identify a compatible compression site of the common peroneal nerve (CPN) during hyper-flexion of knees. To evaluate the course of the CPN at the popliteal area related with compressive neuropathy using magnetic resonance imaging (MRI) scans of healthy Koreans. Methods : 1.5-Tesla knee MRI scans were obtained from enrolled patients and were retrospectively reviewed. The normal populations were divided into two groups according to the anatomical course of the CPN. Type I included subjects with the CPN situated superficial to the lateral gastocnemius muscle (LGCM). Type II included subjects with the CPN between the short head of biceps femoris muscle (SHBFM) and the LGCM. We calculated the thickness of the SHBFM and posterior elongation of this muscle, and the LGCM at the level of femoral condyles. In type II, the length of popliteal tunnel where the CPN passes was measured. Results : The 93 normal subjects were included in this study. The CPN passed through the "popliteal tunnel" formed between the SHBFM and the LGCM in 36 subjects (38.7% type II). The thicknesses of SHBFM and posterior portions of this muscle were statistically significantly increased in type II subjects. The LGCM thickness was comparable in both groups. In 78.8% of the "popliteal tunnel", a length of 21 mm to <40 mm was measured. Conclusion : In Korean population, the course of the CPN through the "popliteal tunnel" was about 40%, which is higher than the Western results. This anatomical characteristic may be helpful for understanding the mechanism of the CPNe by posture.

• Archives of Reconstructive Microsurgery
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• v.14 no.1
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• pp.57-62
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• 2005

Microvascular anastomosis with suture technique is a basic skill but there are several problems such as stenosis, thrombosis and long operating time. Recently plastic surgeons have developed non-suturing mechanical coupling devices for microvascular anastomosis. The authors applied non-penetrating vascular clips (VCS clips) in the field of free flap surgery of head and neck area. Between August of 2004 and January of 2005, we performed 9 free flaps (16 vessels) using small-sized VCS clips. Four stay sutures were applied first and then VCS clips were placed between sutures about 1 mm apart. Vascular pedicle of free flap included the descending branch of lateral circumflex femoral vessel, thoracodorsal vessel, deep inferior epigastric vessel and cephalic vein. The recipient vessels were the superior thyroid artery, superficial temporal artery, internal jugular vein, external jugular vein, and superficial temporal vein. We performed 13 end-to-end (4 arteries and 9 veins) and 3 venous end-to-side anastomoses. No flap related complication occurred but we applied additional clips or sutures in two cases due to blood leakage after completion of anastomosis. Primary patency rates seemed to be good and more rapid anastomosis could be done than conventional suture technique. Advantages of VCS technique are high patency rate, low thrombogenecity and rapidity. Although the high cost of VCS instrument may be a problem, this clip could be applied safely in microvascular free tissue transfer.

• Tribology and Lubricants
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• v.21 no.5
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• pp.216-220
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• 2005

The sliding wear behaviors of three different compositions of novel low temperature degradation-free zirconia/alumina (LTD-free Z/A) composites were examined in a ceramic-ceramic contact pair. The wear tests were performed by using a pin-on-disk type wear tester in a linear reciprocal sliding motion with a line contact in both dry and bovine serum lubricated conditions at room temperature. From the results of dry sliding wear tests, Z/A#1((5.3Y, 4.6Nb)-TZP/80 $vol\%Al_2O_3$) showed the best wear resistance among three kinds of LTD-free Z/A composites. For the bovine serum lubricated sliding wear tests, wear was too little to be measured for all kinds of Z/A composites. These novel LTD-free Z/A composites having excellent wear resistance demonstrated a potential as the alternative materials for the ceramic-ceramic contact pairs of femoral head and acetabular liner in total hip replacement.