• Title/Summary/Keyword: Comparative clinical study

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Dosimetric Characteristics on Penumbra Regions of the Multileaf Collimator as Compared with the Lead Alloy Block (다엽 콜리메이터(Multileaf Collimator)와 합금납 차폐물(Lead Alloy Block)의 반 그림자영역의 선량 분포상의 특성 비교)

  • Lee Sang Wook;Oh Young Tack;Kim Woo Cheol;Keum Ki Chang;Yoon Seong Ick;Kim Hyun Soo;Park Won;Chu Seong Sil;Kim Gwi Eon
    • Radiation Oncology Journal
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    • v.13 no.4
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    • pp.391-396
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    • 1995
  • Purpose : The Conformal Radiation Therapy has bee widely used under favour of development of computer technologies. The delivery of a large number of static radiation fields are being necessary for the conformal irradiation. In this paper we investigate dosimetric characteristics on penumbra regions of a multileaf collimator(MLC), and compare to those of lead alloy block for the optimal use of the system in 3-D conformal radiotherapy. Materials and Methods : The measurement of penumbra by MLC or lead alloy block was performed with 6 or 10 MV X-rays. The film was positioned at a dmax depth and 10 cm depth, and its optical density was determined using a scanning videodensitometer. The effective penumbra, the distance from $80{\%}$ to $20{\%}$ isodose lines and $90{\%}$ to $10{\%}$ were analyzed as a function of the angle between the direction of leaf motion and the edge defined by leaves. Results : Increasing MLC angle ($0-75^{\circ}$) was observed with increasing the penumbra widths and the scalloping effect. There was no definite differences of penumbra width from $80{\%}$ to $20{\%}$ isodose lines, while being the small increase of penumbra width from $90{\%}$ to $10{\%}$ isodose line varing the depth and energy. The effective penumbra width of lead alloy block are agree resonably with those of MLC within 4.8mm. Conclusion : The comparative qualitative study of the penumbra between MLC and lead alloy block demonstrate the clinical acceptability and suitability of the multileaf collimator for 3-D conformal radiotherapy.

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A Study on the Characteristics of Descriptions of the Perspiration in "Hwangjenaegyeong(黃帝內經)" (황제내경(黃帝內經)에 보이는 한(汗)관련 서술(敍述)의 특징(特徵)에 대한 고찰(考察))

  • Lyu, Jeong-Ah;Jang, Woo-Chang;Baik, You-Sang;Jeong, Chang-Hyun
    • Journal of Korean Medical classics
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    • v.23 no.2
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    • pp.205-223
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    • 2010
  • In Korean Traditional Medicine(abbreviated to K.T.M.), hyperhidrosis and anhidrosis are the targets of the medical treatment. Furthermore sweating appearance is also one of the important symptoms which explain a particular situation of the patient in K.T.M. And at "Sanghanron(傷寒論)" which is a traditional chief clinical bible written by Jang Gi(張機) later Han dynasty(漢代) in China made full use of the various kinds of diaphoresis[汗法] as a main medical treatment with purgation therapy[下法] and emetic therapy[吐法]. So the sweat in itself not only is the disease, but also is one of the symptoms explain a disease pattern. This thesis inquires into "Hwangjenaegyeong(黃帝內經)" referring to sweat which is the origin of recognition to the sweat in K.T.M. Some theses similar to this research had been made progresses and already reported, but most of them have classified the contents into biology, pathology, diagnosis, treatment after the model of western medical theory. In the aspect of comparative studying with other literature and clinic practical using, we found characteristics of referring to sweat in "Hwangjenaegyeong(黃帝內經)". And we classify the characteristics into some categories as follows. 1. There are some terms which make a title including sweat and symbolize the characteristics, for example sweat of soul[魄汗], sweat of death[絶汗], sweat of streaming[灌汗], sweat of weakness[白汗], sweat of sleep[寢汗], sweat of bright and heat[炅汗], sweat of kidney[腎汗], sweat of escaping[漉汗], cold sweat[寒汗], sweat on the head[頭汗], hyperhidrosis[多汗], heavy sweat[大汗]. But there aren't spontaneous sweat[自汗] or sweat like a thief[盜汗] which are the normal terms referring to sweat in history of K.T.M. And there are several descriptions about sweat appearance such as sweating in half of body[汗出偏沮], sweating in the rear end and thigh and knee[汗出尻陰股膝], hyperhidrosis in the neck and aversion to wind[頸多汗惡風], hyperhidrosis in the head and face and aversion to wind[頭面多汗惡風], cannot stopping the sweating under head[頭以下汗出不可止], make a person sweat to one's feet[令汗出至足], sweating like escaping[漯漯然汗出], sweating like soaking[汗出如浴], sweating become moist[汗出溱溱], hardly escaping sweat[汗大泄], escaping sweating[漉漉之汗], sweat moisten the pores [汗濡玄府], ceaseless sweating like pouring[汗注不休] sweating like pouring and vexation[汗注煩心], damp with sweat[汗汗然], sweating spontaneously[汗且自出], removal of fever with sweat drying[熱去汗稀]. That can be divided into sweat region and sweat form. 2. There are detailed explanations of the principle of perspirations caused by hot weather, hot food, hard working and meeting damp pathogen. 3. There are some explanations of the principle of removing fever due to the excessive heat from internal and external body through sweating by replenishing the body fluid. And many descriptions about overcoming the febrile disease by dropping temperature through sweating and many diaphoresis for curing. 4. There are some descriptions about five Jang organs perspirations and attachment of five mucous body fluid to five Jang organs. 5. There are pathogenic progresses after sweating affected by the Six Atmospheric Influences and water. And detailed explanations of disease mechanism a sweat leading to another disease. 6. There are descriptions about various sweat absent situations.

Therapeutic use of percussion instruments for children with aggressive behaviors - Case studies with quantitative and qualitative approaches - (공격성 아동을 위한 음악치료 -타악기 연주활동 중심의 사례연구-)

  • Han, Jee hyun
    • Journal of Music and Human Behavior
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    • v.2 no.2
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    • pp.33-56
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    • 2005
  • The purpose of this study is to measure the effect of musical activities on children's aggressiveness using percussion playing through case studies and to present the therapeutic programs. Musical activities using percussion playing were organized for three aggressive children. Twenty-one small group sessions were conducted over seven weeks with 30 minutes given each session. Fourth-grade children involved in using Aggressiveness Measuring Tool for Teachers-revised by Gwak Geum-Joo(1992) was selected for case studies. Children's impulsiveness was also tested through self-test measuring tool for impulsiveness-revision of 16 questions used by Cho Hae Yeon (2001) and Lee Joo Shik (2003). As quantitative method, comparative analysis was made between the pre and post test results using measuring tools for aggressiveness and impulsiveness of children as well as between aggressive behaviors occurring in the initial stage of the first three sessions and in the latter stage of the last three sessions. Qualitative method was used at the same time to examine the effect of percussion playing on children. After the musical activities, child A showed reduced Aggressive Measuring Tool scores from 19 to 18, with child B from 23 to 19 and child C from 21 to 18. The results show that occurrence of aggressive behaviors were lowered in the post test. Impulsiveness Measuring Tool scores in the post test were decreased as well in all three children. During the music therapy programs, it was also observed that the frequency of the target behaviors in all three children has reduced more in the latter stage than the initial stage of music therapy. The qualitative findings indicate that the children experienced releasing stress through self-expression after percussion playing. These findings indicate therapeutic effectiveness of music therapy using on percussion playing in reducing aggressiveness of children as well as the effectiveness of percussion as a therapeutic intervention for aggressive children. These results can be adapted and reapplied by teachers in primary schools to approach children with behavior problems, and can present a useful therapeutic approach to therapists practicing in clinical environments.

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Comparative evaluation of marginal and internal fit of metal copings fabricated by various CAD/CAM methods (다양한 CAD/CAM 방식으로 제작한 금속하부구조물 간의 변연 및 내면 적합도 비교 연구)

  • Jeong, Seung-Jin;Cho, Hye-Won;Jung, Ji-Hye;Kim, Jeong-Mi;Kim, Yu-Lee
    • The Journal of Korean Academy of Prosthodontics
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    • v.57 no.3
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    • pp.211-218
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    • 2019
  • Purpose: The purpose of the present study was to compare the accuracy of four different metal copings fabricated by CAD/CAM technology and to evaluate clinical effectiveness. Materials and methods: Composite resin tooth of the maxillary central incisor was prepared for a metal ceramic crown and duplicated metal die was fabricated. Then scan the metal die for 12 times to obtain STL files using a confocal microscopy type oral scanner. Metal copings with a thickness of 0.5 mm and a cement space of $50{\mu}m$ were designed on a CAD program. The Co-Cr metal copings were fabricated by the following four methods: Wax pattern milling & Casting (WM), Resin pattern 3D Printing & casting (RP), Milling & Sintering (MS), Selective laser melting (SLM). Silicone replica technique was used to measure marginal and internal discrepancies. The data was statistically analyzed with One-way analysis of variance and appropriate post hoc test (Scheffe test) (${\alpha}=.05$). Results: Mean marginal discrepancy was significantly smaller in the Group WM ($27.66{\pm}9.85{\mu}m$) and Group MS ($28.88{\pm}10.13{\mu}m$) than in the Group RP ($38.09{\pm}11.14{\mu}m$). Mean cervical discrepancy was significantly smaller in the Group MS than in the Group RP. Mean axial discrepancy was significantly smaller in the Group WM and Group MS then in the Group RP and Group SLM. Mean incisal discrepancies was significantly smaller in the Group RP than in all other groups. Conclusion: The marginal and axial discrepancies of the Co-Cr coping fabricated by the Wax pattern milling and Milling/Sintering method were better than those of the other groups. The marginal, cervical and axial fit of Co-Cr copings in all groups are within a clinically acceptable range.

An Optimization Method of Measuring Heart Position in Dynamic Myocardial Perfusion SPECT with a CZT-based camera (동적 심근관류 SPECT에서 심장의 위치 측정방법에 대한 고찰)

  • Seong, Ji Hye;Lee, Dong Hun;Kim, Eun Hye;Jung, Woo Young
    • The Korean Journal of Nuclear Medicine Technology
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    • v.23 no.1
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    • pp.75-79
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    • 2019
  • Purpose Cadmium-zinc-telluride (CZT) camera with semiconductor detector is capable of dynamic myocardial perfusion SPECT for coronary flow reserve (CFR). Image acquisition with the heart positioned within 2 cm in the center of the quality field of view (QFOV) is recommended because the CZT detector based on focused multi-pinhole collimators and is stationary gantry without rotation. The aim of this study was to investigate the optimal method for measuring position of the heart within the center of the QFOV when performing dynamic myocardial perfusion SPECT with the Discovery NM 530c camera. Materials and Methods From June to September 2018, 45 patients were subject to dynamic myocardial perfusion SPECT with D530c. For accurate heart positioning, the patient's heart was scanned with a mobile ultrasound and marked at the top of the probe where the mitral valve (MV) was visible in the parasternal long-axis view (PLAX). And, the marked point on the patient's body matched with the reference point indicated CZT detector in dynamic stress. The heart was positioned to be in the center of the QFOV in rest. The coordinates of dynamic stress and rest were compared statistically. Results The coordinates of the dynamic stress using mobile ultrasound and those taken of the rest were recorded for comparative analysis with regard to the position of the couch and analyzed. There were no statistically significant differences in the coordinates of Table in & out, Table up & down, and Detector in & out (P > 0.05). The difference in distance between the 2 groups was measured at $0.25{\pm}1.00$, $0.24{\pm}0.96$ and $0.25{\pm}0.82cm$ respectively, with no difference greater than 2 cm in all categories. Conclusion The position of the heart taken using mobile ultrasound did not differ significantly from that of the center of the QFOV. Therefore, The use of mobile ultrasound in dynamic stress will help to select the correct position of the heart, which will be effective in clinical diagnosis by minimizing the image quality improvement and the patient's exposure to radiation.

Preservation of the Posterior Ligaments for Preventing Postoperative Spinal Instability in Posterior Decompression of Lumbar Spinal Stenosis: Comparative Study between Port-Hole Decompression and Subtotal Laminectomy (요추부 척추관 협착증의 후방 감압술에서 후방 인대의 보존 여부와 술 후 척추 불안정성과의 연관성: 포트홀(Port-Hole) 감압술과 후궁 아전절제술 간 비교 연구)

  • Jung, Yu-Hun;Na, Hwa-Yeop;Choe, Saehun;Kim, Jin;Lee, Joon-Ha
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.1
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    • pp.71-77
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    • 2020
  • Purpose: To determine if sparing the interspinous and supraspinous ligaments during posterior decompression for lumbar spinal stenosis is significant in preventing postoperative spinal instability. Materials and Methods: A total of 83 patients who underwent posterior decompression for lumbar spinal stenosis between March 2014 and March 2017 with a minimum one-year follow-up period, were studied retrospectively. The subjects were divided into two groups according to the type of surgery. Fifty-six patients who underwent posterior decompression by the port-hole technique were grouped as A, while 27 patients who underwent posterior decompression by a subtotal laminectomy grouped as B. To evaluate the clinical results, the Oswestry disability index (ODI), visual analogue scale (VAS) for both back pain (VAS-B) and radiating pain (VAS-R), and the walking distance of neurogenic intermittent claudication (NIC) were checked pre- and postoperatively, while simple radiographs of the lateral and flexion-extension view in the standing position were taken preoperatively and then every six months after to measure anteroposterior slippage (slip percentage), the difference in anteroposterior slippage between flexion and extension (dynamic slip percentage), angular displacement, and the difference in angular displacement between flexion and extension (dynamic angular displacement) to evaluate the radiological results. Results: The ODI (from 28.1 to 12.8 in group A, from 27.3 to 12.3 in group B), VAS-B (from 7.0 to 2.6 in group A, from 7.7 to 3.2 in group B), VAS-R (from 8.5 to 2.8 in group A, from 8.7 to 2.9 in group B), and walking distance of NIC (from 118.4 m to 1,496.2 m in group A, from 127.6 m to 1,481.6 m in group B) were improved in both groups. On the other hand, while the other radiologic results showed no differences, the dynamic angular displacement between both groups showed a significant difference postoperatively (group A from 6.2° to 6.7°, group B from 6.5° to 8.4°, p-value=0.019). Conclusion: Removal of the posterior ligaments, including the interspinous and supraspinous ligaments, during posterior decompression of lumbar spinal stenosis can cause a postoperative increase in dynamic angular displacement, which can be prevented by the port-hole technique, which spares these posterior ligaments.

A comparative study of the puberty suppression effect of gonadotropin-releasing hormone agonist in precocious or early puberty girls (중추성 성조숙증 및 조기 사춘기 여아에서 성선자극호르몬 방출호르몬작용제의 용량에 따른 사춘기 억제 효과 비교)

  • Shim, Kye-Shik;Bae, Chong-Woo;Yang, You-Jung
    • Clinical and Experimental Pediatrics
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    • v.51 no.6
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    • pp.634-639
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    • 2008
  • Purpose : There has been considerable disagreement regarding the most appropriate dosage of gonadotropin-releasing hormone agonist in cases of central precocious puberty. The aim of this study was to determine the appropriate dosage for suppression of the puberty in girls with central precocious or early puberty. Methods : Twenty-two girls with early puberty were randomly subjected to 3 types of dosages of leuprolide acetate for at least 6 months. The number of cases in groups 1, 2, and 3 were 7, 7, and 8, and dosages were 70, 90, and $110{\mu}g/kg/-month$, respectively. Height, weight, bone age, Tanner stage of breast development, and serum levels of LH, FSH, estradiol, and progesterone were measured before treatment and after 6 months of treatment. The number of cases of puberty suppression was compared using a modified puberty suppression score with a nonparametric chi-square test. Results : There were no significant differences of chronologic and bone ages among the groups. There was a significant decrease in height SDS gain after 6 months in group 3 (P<0.05) compared with groups 1 and 2. Serum levels of LH, FSH, estradiol and progesterone were all significantly decreased after treatment in all 3 groups (P<0.05). The number of cases of puberty suppression in each group were 4 (57%), 5 (71%), and 8 (100%). There was a significantly increased proportion of suppression of puberty in group 3 (P<0.05). Conclusion : It was necessary to use a higher dose of gonadotropin-releasing hormone agonist to suppress early puberty in girls; however further longitudinal study will be needed for their prognosis of final adult height.

A Comparative Study on the Pattern of Outpatient Department Utilization at a Tertiary Level Hospital before and after Implementation of the Patient Referral System (의료전달체계 실시 전후의 3차 진료기관 외래환자 이용양상 비교)

  • Lee, Kyeong-Soo;Kim, Chang-Yoon;Kang, Pock-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.25 no.1 s.37
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    • pp.88-100
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    • 1992
  • This study was conducted to assess the effects of implementation of the patient referral system started July 1st, 1989. A comparison on the pattern of outpatient services of the Departments of Internal Medicine, General Surgery, and Pediatrics at the Yeungnam University Hospital was conducted for each one year period before and after implementation of the patient referral system. The pre-implementation period was from July 1, 1988 to June 30, 1989 and the post-implementation period was from July 1, 1989 to June 30, 1990. The information used for this study was obtained from official forms, prepared by the Yeungnam University Hospital, and submitted to the Korean Medical Insurance Cooperatives. After implementation of the patient referral system, the number of outpatient cases in the Department of Internal Medicine decreased 36.1% from 9,669 cases to 6,181 cases a year. Cases in the Department of General Surgery decreased 23.7% from 1,864 cases to 1,422 cases a year. The number of cases in the Department of Pediatrics decreased 36.9% from 3,372 cases to 2,128 cases a year. After implementation of the patient referral system, the average age of cases in the Departments of Internal Medicine and General Surgery was 52.5 and 49.7 years old, respectively. This was a significant increase in comparison with the pre-implementation period. After implementation of patient referral system, the proportion of new outpatients in the Department of Internal Medicine decreased from 24.1% to 14.6%, the Department of General Surgery from 36.0% to 23.4%, and the Department of Pediatrics from 15.5% to 8.3%. The number of visits per case decreased significantly in the Department of Internal Medicine(from 1.74 to 1.61), but there was no significant change in the Departments of General Surgery and Pediatrics. The length of treatment per case increased significantly in all three departments(from 16.1 days to 19.3 days in the Department of Internal Medicine, from 12.0 days to 15.2 days in the Department General Surgery, and 8.9 days to 11.2 days in the Department of Pediatrics). The number of clinical tests per case increased significantly in the Department of Internal Medicine (from 2.2 to 2.5), in the Department of Pediatrics(from 0.8 to 1.1) and increased in the Department of General Surgery(from 6.4 to 6.6). The average medical cost per case decreased from 43,900 Won to 42,500 Won in the Department of Internal Medicine, while the cost increased from 75,900 Won to 78,500 Won in the Department of General Surgery and from 12,700 Won to 13,500 Won in the Department of Pediatrics. In case-mix, the chronic degenerative disease(i. e. hypertension, diabetes mellitus, angina pectoris, malignant neoplasm, and pulmonary tuberculosis) ranked higher and acute infectious diseases and simple cases(i. e. gastritis and duodenitis, haemorrhoids, anal fissure, carbuncle, acute URI, and bronchitis) ranked lower after implementation of the patient referral system compared to before implementation.

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Prognostic Relevance of WHO Classification and Masaoka Stage in Thymoma (흉선종양에서의 WHO 분류와 Masaoka 병기, 임상양상간의 상관관계연구)

  • Kang Seong Sik;Chun Mi Sun;Kim Yong Hee;Park Seung Il;Eeom Dae W.;Ro Jaee Y.;Kim Dong Kwan
    • Journal of Chest Surgery
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    • v.38 no.1 s.246
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    • pp.44-49
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    • 2005
  • Although thymomas are relatively common mediastinal tumors, to date not only has a universal system of pathologic classification not been established but neither has a clearly defined predictable relationship between treatment and prognosis been made. Recently, a new guideline for classification was reported by WHO, and efforts, based on this work, have been made to better define the relationship between treatment and pro­gnostic outcome. In the present study a comparative analysis between the WHO classification and Masaoka stage system with the clinical disease pattern was conducted. Material and Method: A total of 98 patients undergoing complete resection for mediastinal thymoma between Juanuary 1993 and June 2003 were included in the present study. The male female ratio was 48 : 50 and the mean age at operation was $49.6{\pm}13.9\;years.$ A retrospective analytic comparison studying the relationship between the WHO classification and the Masaoka stage system with the clinical disease pattern of thymoma was conducted. Pathologic slide specimens were carefully examined, details of postoperative treatment were documented, and a relationship with the prognostic outcome and recurrence was studied. Result: There were 7 patients in type A according to the WHO system of classification, 14 in AB, 28 in B 1, 23 in B2, 18 in B3, and 9 in type C. The study of the relationship between the Masaoka stage and WHO classification system showed 4 patients to be in WHO system type A, 7 in type AB, 22 in B 1, 17 in B2, and 3 in type B3 among 53 $(54{\%})$ patients shown to be in Masaoka stage I. Among 28 $(28.5{\%})$ patients in Masaoka stage II system, there were 2 patients in type A, 7 in AB, 4 in B 1, 2 in B2, 8 in B3, and 5 in type C. Among 15 $(15.3{\%})$ in Masaoka stage III, there were 1 patient in type B1, 3 in B2, 7 in B3, and 4 in type C. Finally, among 2 $(2{\%})$ patients found to be in Masaoka stage IV there was 1 patient in type B1, and 1 in type B2. The mean follow up duration was $28{\pm}6.8$ months. There were 3 deaths in the entire series of which 2 were in type B2 (Masaoka stages III and IV), and 1 was in type C (Masaoka stage II). Of the patients that experienced relapse, 6 patients remain alive of which 2 were in type B2 (Masaoka III), 2 in type B3 (Masaoka I and III) and 2 in type C (Masaoka stage II). The 5 year survival rate by the Kaplan-Meier method was $90{\%}$ for those in type B2 WHO classification system, $87.5{\%}$ for type C. The 5 year freedom from recurrence rate was $80.7{\%}$ for those in WHO type B2, $81.6{\%}$ for those in type B3, and $50{\%}$ for those in type C. By the Log-Rank method, a statistically significant correlation between survival and recurrence was found with the WHO system of classification (p<0.05). An analysis of the relationship between the WHO classification and Masaoka stage system using the Spearman correction method, showed a slope=0.401 (p=0.023), showing a close correlation. Conclusion: As type C of the WHO classification system is associated with a high postoperative mortality and recurrence rate, aggressive treatment postoperatively and meticulous follow up are warranted. The WHO classification and Masaoka stage system were found to have a close relationship with each other and either the WHO classification method or the Masaoka stage system may be used as a predict prognostic outcome of Thymoma.

The Comparative Imaging Study on Mn-phthalocyanine and Mangafodipir trisodium in Experimental VX2 Animal Model (실험적으로 유발시킨 VX2 동물모델에서의 Mn-phthalocyanine과 Mangafodipir trisodium의 비교영상)

  • Park Hyun-Jeong;Ko Sung-Min;Kim Yong-Sun;Chang Yongmin
    • Investigative Magnetic Resonance Imaging
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    • v.8 no.1
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    • pp.32-41
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    • 2004
  • Purpose : To measure the NMR relaxation properties of MnPC, to observe the characteristics of liver enhancement patterns on MR images in experimentally implanted rabbit VX2 tumor model, and to estimate the possibility of tissue specific contrast agent for MnPC in comparison with the hepatobiliary agent. Materials and Methods : Phthalocyanine (PC) was chelated with paramagnetic ions, manganese (Mn). 2.01 g (5.2 mmol) of phthalocyanine was mixed with 0.37 g (1.4 nlmol) of Mn chloride at $310^{\circ}C$ for 36 hours and then purified by chromatography ($CHCl_3:\;CH_3OH=98:2$, volume ratio) to obtain 1.04 g $(46\%)$ of MnPC (molecular weight = 2000 daltons). The T1/T2 relaxivity (R1/R2) for MnPC were determined at a 1.5 T (64 MHz) MR spectrometer. VX2 tumor model was experimentally implanted in the liver parenchyma of rabbits. All MR studies were performed on 1.5 T. The human extremity radio frequency coil of a bird cage type was employed. MR images were acquired at 17 to 24 days after VX2 carcinoma implantation.4 mmol/kg MnPC and 0.01 mmol/kg Mn-DPDP were injected via the ear vein of rabbits. T1-weighted images were obtained with spin-echo (TR/TE=516/14 msec) and fast multiplanar spoiled gradient recalled (TR/TE : 80/4 msec, $60^{\circ}$ flip angle) pulse sequence. Fast spin-echo (TR/TE=1200/85 msec) was used to obtain the T2-weighted images. Results : The value of T1/T2 relaxivity (R1/R2) of MnPC was $7.28\;mM^{-1}S^{-1}$ and $55.56\;mM^{-1}S^{-1}$ respectively at 1.5 T (64 MHz). Because the T2 relaxivity of MnPC that bonded strongly, covalently manganese with phthalocyanine was very high, the signal intensity of liver parenchyma was decreased on postcontrast T2-weighted images and we could easily distinguish the VX2 carcinoma within the liver parenchyma. When MnPC was administrated intravenously, the tumor margin delineation was more remarkable than Mn-DPDP-enhanced images. The enhancement of liver parenchyma with MnPC persisted at relatively high levels over at least one hour after injection of the contrast agents. Conclusion : The hepatic uptake and biliary excretion of MnPC, which are similar to Mn-DPDP, suggest that this agent is a new liver-specific agent. Also, MnPC seems to be used as a dual contrast agent (T1 and T2) with high T2 relaxivity. However, it is warranted that MnPC needs further investigation as a potential contrast agent for MR imaging of the liver. That is, further characterizations of MnPC are needed in vivo and in vitro before clinical trials. The diagnostic potential of MnPC will also have to be examined more in the animal models of additional types.

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