• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.18-24
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• 2012

Purpose : Although lung ventilation SPECT (LV-SPECT) has a good sensitivity in detection of deep lung lesions, it is difficult to apply the LV-SPECT to patients having breathing problems due to limited examination time. In this study, we evaluated the usefulness of LEAP collimator, which provides high detection sensitivity and tolerable resolution, for the LV-SPECT in terms of diagnostic accuracy and examination time. Materials and Methods : Four volunteers inhaled Technegas (370 MBq) and the lung ventilation planar scan (LVPS, 300 counts/view (cpv)) with LEHR collimator was performed using Siemens E.cam scanner as a reference test. LV-SPECT scans were performed with three collimators, LEHR, LEUHR, and LEAP, in low (7 kcpv) and high (70 kcpv) counting modes. The count ratios of left (LT) and right (RT) lung segments were calculated on the geometric mean view of anterior and posterior images for LVPS and on the summed coronal images of LV-SPECT, respectively. Comparing to LVPS, the usefulness of three different collimators for LV-SPECT was evaluated through statistical analysis (paired t-test), on count ratios of lung segments. Results : The average LT:RT ratio in LVPS was 47:53. For LV-SPECT, there were negligible difference of the LT:RT ratios (48:52 on average) among three different collimators in low and high counting modes. Comparing to standard LVPS with LEHR, all LV-SPECTs with different collimators resulted in similar diagnostic accuracy through paired t-test (p>0.05). The scan time in LVPS (6 views) was 17.3 min. For LV-SPECT (128 views) in low counting mode, it took 18.7 (LEUHR), 15.0 (LEHR), and 12.3 min (LEAP), respectively. Conclusion : Comparing to standard LVPS, the LV-SPECT with LEAP in low counting mode provided the comparable diagnostic accuracy in addition to shortened scan time.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.139-146
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• 2002

Purpose : This study evaluated the treatment outcomes, patterns of failure, and treatment related complications of primary lymphoma patients who received definitive radiation therapy. Materials and Methods : A retrospective analysis was undertaken for 31 patients with primary orbital lymphoma at the Asan Medical Center between February 1991 and April 2001. There were 18 males and 13 females with ages ranging from 3 to 73 years (median, 44 years). The involved sites were 9 conjunctivae, 12 eyelids and 10 other orbits. The histological types were 28 MALT lymphomas (low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type), 1 diffuse large B-cell lymphoma, 1 anaplastic large cell lymphoma and 1 lymphoblastic lymphoma. The Ann Arbor stages were all IE $(100\%)$. Ann Arbor stage III or IV patients were excluded from this study, Bilateral orbital involvement occurred in 6 cases. Radiation therapy was given with one anterior port of high energy electrons $(6\~16\;MeV)$ for the lesions located at the anterior structures like the conjunctivae or eyelids. Lesions with a posterior extension or other orbital lesions were treated with 4 or 6 MeV photons with appropriately arranged portals. In particular, lens blocks composed of lead alloy were used in conjunctival or eyelid lesions. Twelve patients received chemotherapy. The median follow-up period was 53 months. Results : The 5-year overall, cause-specific, and disease-free survival was $91\%,\;96\%,\;and\;80\%$, respectively. The complete response rate 6 months after radiation therapy was $100\%$. Local recurrences were observed in 2 patients at 16 and 18 months after completion of radiation treatment. They were salvaged with additional radiation therapy. Two patients developed distant metastases. A MALT lymphoma patient with a lung relapse was successfully salvaged with radiotherapy, but the other lymphoblastic lymphoma patient with bone marrow relapse expired. There were no severe complications but 5 patients developed radiation-induced cataracts and 2 patients developed dry eye. Conclusion : Most primary orbital lymphomas consisted of MALT lymphomas. Radiation therapy was a successful treatment modality for orbital lymphoma without any severe complications. In cases of local relapses, radiation therapy is also a very successful salvage treatment modality.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.1-10
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• 2000

Purpose : Although using the high energy Photon beam with conventional Parallel-opposed beams radiotherapy for nasopharyngeal carcinoma, radiation-induced xerostomia is a troublesome problem for patients. We conducted this study to explore a new parotid gland sparing technique in 3-D conformal radiotherapy (3-D CRT) in an effort to prevent the radiation-induced xerostomia. Materials and Methods : We peformed three different planning for four clinically node-negative nasopharyngeal cancer patients with different location of tumor(intracranial extension, nasal cavity extension, oropharyngeal extension, parapharyngeal extension), and intercompared the plans. Total prescription dose was 70.2 Gy to the isocenter. For plan-A, 2-D parallel opposing fields, a conventional radiotherapy technique, were employed. For plan-B, 2-D parallel opposing fields were used up until 54 Gy and afterwards 3-D non-coplanar beams were used. For plan-C, the new technique, 54 Gy was delivered by 3-D conformal 3-port beams (AP and both lateral ports with wedge compensator; shielding both superficial lobes of parotid glands at the AP beam using BEV) from the beginning of the treatment and early spinal cord block (at 36 Gy) was peformed. And bilateral posterior necks were treated with electron after 36 Gy. After 54 Gy, non-coplanar beams were used for cone-down plan. We intercompared dose statistics (Dmax, Dmin, Dmean, D95, DO5, V95, VOS, Volume receiving 46 Gy) and dose volume histograms (DVH) of tumor and normal tissues and NTCP values of parotid glands for the above three plans. Results : For all patients, the new technique (plan-C) was comparable or superior to the other plans in target volume isodose distribution and dose statistics and it has more homogenous target volume coverage. The new technique was most superior to the other plans in parotid glands sparing (volume receiving 46 Gy: 100, 98, 69$\%$ for each plan-A, B and C). And it showed the lowest NTCP value of parotid glands in all patients (range of NTCP; 96$\~$100$\%$, 79$\~$99$\%$, 51$\~$72$\%$ for each plan-A, B and C). Conclusion : We conclude that the new technique employing 3-D conformal radiotherapy at the beginning of radiotherapy and cone down using non-coplanar beams with early spinal cord block is highly recommended to spare parotid glands for node-negative nasopharygeal cancer patients.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.27-31
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• 2000

Purpose : The aim of this study was to investigate treatment results, toxicity and efficacy of hypefractionated radiation therapy combined with paclitaxel for paraaortic node recurrence in cervix cancer. Materials and Methods: Between September 1997 to March 1999, 12 patients with paraaortic node recurrence in cervix cancer who previously received radical or postoperative radiotherapy were treated with hypefractionated radiation therapy combined with paclitaxel. Of these, 2 patients who irradiated less than 30 Gy were excluded, 10 patients were eligible for this study. Median age was 51 years. Initial FIGO stage was 1 stage IBI, 2 stage IIA, 7 stage IIB. For initial treatment, 7 patients received radical radiotherapy and 3 received postoperative radiotherapy. The paraaortic field encompassed the gross recurrent disease with superior margin at T12, and inferior margin was between L5 and S1 with gap for previously pelvic radiation field. The radiation field was initially anterior and posterior opposed field followed by both lateral field. The daily dose was 1.2 Gy, twice daily fractions, and total radiotherapy dose was between 50.4 and 60 Gy(median, 58.8 Gy). Concurrent chemotherapy was done with paclitaxel as a radiosensitizer. Dose range was from 20 mg/m$^{3}$ to 30 mg/m$^{3}$ (median, 25 mg/m$^{3}$), and cycle of chemotherapy was from 3 to 6 (median, 4.5 cycle). Follow-up period ranged from 3 to 21 months. Results : Interval between initial diagnosis and paraaortic node recurrence was range from 2 to 63 months (median, 8 months). The 1 year overall survival rate and median survival were 75$\%$ and 9.5 months, respectively. The 1 year disease free survival rate and median disease free survival were 30$\%$ and 7 months, respectively. At 1 month after treatment, 4 (40$\%$) achieved a complete response and 6 (60$\%$) experienced a partial response and all patients showed response above the partial response. There was distant metastasis in 6 patients and pelvic node recurrence In 2 patients after paraaortic node irradiation. There was 2 patients with grade 3 to 4 leukopenla and 8 patients with grade 1 to 2 nausea/ vomiting which was usually tolerable with antlemetic drug. There was no chronic complication in abdomen and pelvis during follow up period. Conclusion : hypefractionated radiation therapy combined with paclitaxel chemotherapy diosensitizer showed high response rate and few complication rate in paraaortic node recurrence in cervix cancer Therefore, present results suggest that hypefractionated radiation therapy combined with paclitaxel chemotherapy can be used as optimal treatment modality in this patients.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.91-99
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• 1999

Propose : This study was performed to find out the prognostic factors affecting local control, survival and disease free survival rate in nasopharyngeal carcinomas treated with chemotherapy and radiation therapy. Materials and Methods : We analysed 47 patients of nasopharyngeal carcinomas, histologically confirmed and treated at Chonnam University Hospital between July 1986 and June 1996, retrospectively. Range of patients' age were from 16 to 80 years (median; 52 years). Thirty three (70$\%$) patients was male. Histological types were composed of 3 (6$\%$) keratinizing, 30 (64$\%$) nonkeratinizing squamous cell carcinoma and 13 (28$\%$) undifferentiated carcinoma. Histoiogicai type was not known in 1 patient (2$\%$). We restaged according to the staging system of 1997 American Joint Committee on Cancer Forty seven patients were recorded as follows: 71: 11 (23$\%$), T2a; 6 (13$\%$), T2b; 9 (19$\%$), 73; 7 (15$\%$), 74: 14 (30$\%$), and NO; 7 (15$\%$), Nl: 14 (30$\%$), N2; 21 (45%), N3: 5 (10%). Clinical staging was grouped as follows: Stage 1; 2 (4$\%$), IIA: 2 (4$\%$), IIB; 10 (21$\%$), III; 14 (30$\%$), IVA; 14 (30$\%$) and IVB; 5 (11$\%$). Radiation therapy was done using 6 MV and 10 MV X- ray of linear accelerator. Electron beam was used for the Iymph nodes of posterior neck after 4500 cGy. The range of total radiation dose delivered to the primary tumor was from 6120 to 7920 cGy (median; 7020 cGy). Neoadjuvant chemotherapy was performed with cisplatin +5-fluorouracil (25 patients) or cisplatin+pepleomycin (17 patients) with one to three cycles. Five patients did not received chemotherapy. Local control rate, survival and disease free suwival rate were calculated by Kaplan-Meier method. Generalized Wilcoxon test was used to evaluate the difference of survival rates between groups. multivariate analysis using Cox proportional hazard model was done for finding prognostic factors. Results: Local control rate was 81$\%$ in 5 year. Five year survival rate was 60$\%$ (median survival; 100 months). We included age, sex, cranial nerve deflicit, histologic type, stage group, chemotherapy, elapsed days between chemotherapy and radiotherapy, total radiation dose, period of radiotherapy as potential prognostic factors in multivariate analysis. As a result, cranial none deficit (P=0.004) had statistical significance in local control rate. Stage group and total radiation dose were significant prognostic factors in survival (P=0.000, P=0.012), and in disease free survival rates (P=0.003, P=0.008), respectively. Common complications were xerostomia, tooth and ear problems. Hypothyroidism was developed in 2 patients. Conclusion : In our study, cranial none deficit was a significant prognostic factor in local control rate, and stage group and total radiation dose were significant factors in both survival and disease free survival of nasopharyngeal carcinoma. We have concluded that chemotherapy and radiotherapy used in our patients were effective without any serious complication.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.268-277
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• 2007

Purpose: Respiratory motion is a considerable inhibiting factor for precise treatment with stereotactic radiosurgery using the CyberKnife (CK). In this study, we developed a moving phantom to simulate three-dimensional breathing movement and investigated the distortion of dose profiles between the use of a moving phantom and a static phantom. Materials and Methods: The phantom consisted of four pieces of polyethylene; two sheets of Gafchromic film were inserted for dosimetry. Treatment was planned to deliver 30 Gy to virtual tumors of 20, 30, 40, and 50 mm diameters using 104 beams and a single center mode. A specially designed robot produced three-dimensional motion in the right-left, anterior-posterior, and craniocaudal directions of 5, 10 and 20 mm, respectively. Using the optical density of the films as a function of dose, the dose profiles of both static and moving phantoms were measured. Results: The prescribed isodose to cover the virtual tumors on the static phantom were 80% for 20 mm, 84% for 30 mm, 83% for 40 mm and 80% for 50 mm tumors. However, to compensate for the respiratory motion, the minimum isodose levels to cover the moving target were 70% for the $30{\sim}50$ mm diameter tumors and 60% for a 20 mm tumor. For the 20 mm tumor, the gaps between the isodose curves for the static and moving phantoms were 3.2, 3.3, 3.5 and 1.1 mm for the cranial, caudal, right, and left direction, respectively. In the case of the 30 mm tumor, the gaps were 3.9, 4.2, 2.8, 0 mm, respectively. In the case of the 40 mm tumor, the gaps were 4.0, 4.8, 1.1, and 0 mm, respectively. In the case of the 50 mm diameter tumor, the gaps were 3.9, 3.9, 0 and 0 mm, respectively. Conclusion: For a tumor of a 20 mm diameter, the 80% isodose curve can be planned to cover the tumor; a 60% isodose curve will have to be chosen due to the tumor motion. The gap between these 80% and 60% curves is 5 mm. In tumors with diameters of 30, 40 and 50 mm, the whole tumor will be covered if an isodose curve of about 70% is selected, equivalent of placing a respiratory margin of below 5 mm. It was confirmed that during CK treatment for a moving tumor, the range of distortion produced by motion was less than the range of motion itself.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.22-31
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• 2005

Purpose : To conduct a nationwide survey on the principals in radiotherapy for rectal cancer, and produce a database of Korean Patterns of Care Study. Materials and Methods : We developed web-based Patterns of Care Study system and a national survey was conducted using random sampling based on power allocation methods. Eligible patients were who had postoperative radiotherapy for rectal cancer without gross residual tumor after surgical resection and without previous history of other cancer and radiotherapy to pelvis. Data of patients were Inputted to the web based PCS system by each investigators in 19 institutions. Results : Informations on 309 patients with rectal cancer who received radiotherapy between 1998 and 1999 were collected. Male to female ratio was 59 : 41, and the most common location of tumor was lower rectum ($46\%$). Preoperative CEA was checked in $79\%$ of cases and its value was higher than 6 ng/ml in $32\%$. Pathologic stage were I in $1.5\%$, II in $32\%$, III in $53\%$, and IV in $1.6\%$. Low anterior resection was the most common type of surgery and complete resection was peformed in $95\%$ of cases. Distal resection margin was less than 2 cm in $30\%$, and number of lymph node dissected was less than 12 in $31\%$. Chemotherapy was peformed in $91\%$ and most common regimen was 5-FU and leucovorine ($59\%$). The most common type of field arrangement used for the initial pelvic field was the four field box (Posterior-Right-Left) technique ($65.0\%$), and there was no AP-PA parallel opposing field used. Patient position was prone in $81.2\%$, and the boost field was used in $61.8\%$. To displace bowel outward, pressure modulating devices or bladder filling was used in $40.1\%$. Radiation dose was prescribed to isocenter in $45.3\%$ and to isodose line in 123 cases ($39.8\%$). Percent delivered dose over $90\%$ was achieved in $92.9\%$. Conclusion : We could find the Patterns of Care for the radiotherapy in Korean rectal cancer patients was similar to that of US national survey. The type of surgery and the regimen of chemotherapy were variable according to institutions and the variations of radiation dose and field arrangement were within acceptable range.

• Journal of Korean Medical classics
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• v.9
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• pp.432-552
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• 1996

The influence of the four noted physicians of Geum-Won era(金元代) on the completion of the medicine in the Chosun dynasty(朝鮮朝) can be summarized as follows. 1. The four noted physicians of Geum-Won era were Yoo-Wan-So(劉完素), Jang-Jong-Jung(張從正), Lee-Go(李杲), Ju-Jin-Heung(朱震亨). 2. Yoo-Wan-So(劉完索) made his theory on the basic of Nae-Kyung("內經") and Sane-Han-Lon("傷寒論"), his idea of medicine was characterized in his books, for exemple, application of O-Oon-Yuk-Ki(五運六氣), Ju-Wha theory(主火論) and hang-hae-seng-je theory(亢害承制論). from his theory and method of study, many deviations of oriental medicine occurred. He made an effort for study of Nae-Kyung, which had been depressed for many years, on the contrary of the way old study that Nae-Kyung had been only explained or revised, he applied the theory of Nae-Kyung to clinical care. The theory of Yuk-Gi-Byung-Gi(六氣病機) and On-Yeul-Byung(溫熱病) had much influenced on his students and posterities, not to mention Jang-Ja-Wha and Ju-Jin-Heung, who were among the four noted physicians therefore he became the father of Yuk-Gi(六氣) and On-Yeul(溫熱) schools. 3. Jang-Jong-Jung(張從正) emulated Yoo-Wan-So as a model, and followed his Yuk-Gi-Chi-Byung(六氣致病) theory, but he insisted on the use of the chiaphoretic, the emetic and the paregoric to get rid of the causes, specially he insisted on the use of the paregoric, so they called him Gong-Ha-Pa(攻下派). He insisted on the theory that if we would strenthen ourselves we should use food, id get rid of cause, should use the paregoric, emetic and diaphoretic. Jang-Jong-Jung'S Gang-Sim-Wha(降心火) theory, which he improved Yoo-Wan-So's Han-Ryang(寒凉) theory influenced to originate Ju-Jin-Heung'S Ja-Eum-Gang-Wha(滋陰降火) theory. 4. Lee-Go(李杲) insisted on the theory that Bi-Wi(脾胃) played a loading role in the physiological function and pathological change, and that the internal disease was originated by the need of Gi(氣) came from the disorder of digestive organs, and that the causes of internal disease were the irregular meal, the overwork, and mental shock. Lee-Go made an effort for study about the struggle of Jung-Sa(正邪) and in the theory of the prescription he asserted the method of Seung-Yang-Bo-Gi(升陽補氣), but he also used the method of Go-Han-Gang-Wha(苦寒降火). 5. The authors of Eui-Hak-Jung-Jun("醫學正傳"), Eui-Hak-Ib-Moon("醫學入門"), and Man-Byung-Whoi-Choon("萬病回春") analyzed the medical theory of the four noted physicians and added their own experiences. They helped organizing existing complicated theories of the four noted physicians imported in our country, and affected the formation of medical science in the Choson dynasty largely. Eui-Hak-Jung-Jun("醫學正傳") was written by Woo-Dan(虞槫), in this book, he quoted the theories of Yoo-Wan-So, Jang-Jong-Jung, Lee-Go, Ju-Jin-Heung, especially, Ju-Jin-Heung was respected by him, it affected the writing of Eui-Lim-Choal-Yo("醫林撮要"). Eui-Hak-ib-Moon("醫學入門"), written by Lee-Chun(李杲), followed the medical science of Lee-Go and ju-jin-heung from the four noted physicians of Geum-Won era. Its characteristics of Taoism, idea of caring of health, and organization affected Dong-Eui-Bo-Kham("東醫寶鑑"). Gong-Jung-Hyun(龔延賢) wrote Man-Byung-Whoi-Choon("萬病回春") using the best part of the theories of Yoo-Wan-So, Jang-Jong-Jung, Lee-Go, Ju-Jin-Heung, this book affected Dong-Eui-Soo-Se-Bo-Won("東醫壽世保元") partly. 6. our medical science was developed from the experience of the treatment of disease obtained from human life, these medical knowledge was arranged and organized in Hyang-Yak-Jib-Sung-Bang("鄕藥集成方"), medical books imported from China was organized in Eui-Bang-Yoo-Chwi("醫方類聚"), which formed the base of medical development in the Chosun dynasty. 7. Eui-Lim-Choal-Yo("醫林撮要") was written by Jung-Kyung-Sun(鄭敬先) and revised by Yang-Yui-Soo(楊禮壽). It was written on the base of Woo-Dan's Eui-Jung-Jun, which compiled the medical science of the four noted physicians of Geum-Won era. It contained confusing theories of the four noted physicians of Geum-Won era and organized medical books of Myung era, therefore it completed the basic form of Byun-Geung-Non-Chi (辨證論治) influenced the writing of Dong-Eui-Bo-Kham("東醫寶鑑"). 8. Dong-Eui-Bo-Kham("東醫寶鑑") was written on the base of basic theory of Eum-Yang-O-Haeng(陰陽五行) and the theory of respondence of heaven and man(天人相應說) in Nae-Kyung. It contained several theories and knowledge, such as the theory of Essence(精), vitalforce(氣), and spirit(神) of Taoism, medical science of geum-won era, our original medical knowledge and experience. It had established the basic organization of our medical science and completed the Byun-Geung-Non-Chi (辨證論治). Dong-Eui-Bo-Kham developed medical science from simple medical treatment to protective medical science by caring of health. And it also discussed human cultivation and Huh-Joon's(許浚) own view of human life through the book. Dong-Eui-Bo-Kham adopted most part of Lee-Go(李杲) and Ju-Jin-Heung's(朱震亨) theory and new theory of "The kidney is the basis of apriority. The spleen is the basis of posterior", so it emphasized the role of spleen and kidney(脾腎) for Jang-Boo-Byung-Gi(臟腑病機). It contained Ju-Jin-Heung's theory of the cause and treatment of disease by colour or fatness of man(black or white, fat or thin). It also contained Ju-Jin-Heung's theory of "phlegm break out fever, fever break out palsy"(痰生熱 熱生風) and the theory of Sang-Wha(相火論). Dong-Eui-Bo-Kham contained Lee-Go's theory of Wha-Yu-Won-Bool-Yang-Lib (火與元氣不兩立論) quoted the theory of Bi-Wi(脾胃論) and the theory of Nae-Oi-Sang-Byun(內外傷辨). For the use of medicine, it followed the theory by Lee-Go. lt used Yoo-Wan-So'S theory of Oh-Gi-Kwa-Keug-Gae-Wi-Yul-Byung(五志過極皆爲熱病) for the treatment of hurt-spirit(傷神) because fever was considered as the cause of disease. It also used Jang-Jons-Jung's theory of Saeng-Keug-Je-Seung(生克制勝) for the treatment of mental disease. 9. Lee-je-ma's Dong-Eui-Soo-Se-Bo-Won("東醫壽世保元") adopted medical theories of Song-Won-Myung era and analyzed these theories using the physical constitutional theory of Sa-Sang-In(四象人). It added Dong-Mu's main idea to complete the theory and clinics of Sa-Sang-Eui-Hak(四象醫學). Lee-Je-Ma didn't quote the four noted physicians of Geum-Won era to discuss that the physical constitutional theory of disease and medicine from Tae-Eum-In(太陰人), So-Yang-In(少陽人), So-Eum-In(少陰人), and Tae-Yang-In(太陽人) was invented from their theories.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.736-745
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• 1998

Background: Respiratory muscle interaction is further profoundly affected by a number of pathologic conditions. Hyperinflation may be particularly severe in chronic obstructive pulmonary disease(COPD) patients, in whom the functional residual capacity(FRC) often exceeds predicted total lung capacity(TLC). Hyperinflation reduces the diaphragmatic effectiveness as a pressure generator and reduces diaphragmatic contribution to chest wall motion. Ultrasonography has recently been shown to be a sensitive and reproducible method of assessing diaphragmatic excursion. This study was performed to evaluate how differences of diaphragmatic excursion measured by ultrasonography associate with normal subjects and COPD patients. Methods: We measured diaphragmatic excursions with ultrasonography on 28 healthy subjects(l6 medical students, 12 age-matched control) and 17 COPD patients. Ultrasonographic measurements were performed during tidal breathing and maximal respiratory efforts approximating vital capacity breathing using Aloka KEC-620 with 3.5 MHz transducer. Measurements were taken in the supine posture. The ultrasonographic probe was positioned transversely in the midclavicular line below the right subcostal margin. After detecting the right hemidiaphragm in the B-mode the ultrasound beam was then positioned so that it was approximately parallel to the movement of middle or posterior third of right diaphragm. Recordings in the M-mode at this position were made throughout the test. Measurements of diaphragmatic excursion on M-mode tracing were calculated by the average gap in 3 times-respiration cycle. Pulmonary function test(SensorMedics 2800), maximal inspiratory(PImax) and expiratory mouth pressure(PEmax, Vitalopower KH-101, Chest) were measured in the seated posture. Results: During the tidal breathing, diaphragmatic excursions were recorded $1.5{\pm}0.5cm$, $1.7{\pm}0.5cm$ and $1.5{\pm}0.6cm$ in medical students, age-matched control group and COPD patients, respectively. Diaphragm excursions during maximal respiratory efforts were significantly decreased in COPD patients ($3.7{\pm}1.3cm$) when compared with medical students, age-matched control group($6.7{\pm}1.3cm$, $5.8{\pm}1.2cm$, p< 0.05}. During maximal respiratory efforts in control subjects, diaphragm excursions were correlated with $FEV_1$, FEVl/FVC, PEF, PIF, and height. In COPD patients, diaphragm excursions during maximal respiratory efforts were correlated with PEmax(maximal expiratory pressure), age, and %FVC. In multiple regression analysis, the combination of PEmax and age was an independent marker of diaphragm excursions during maximal respiratory efforts with COPD patients. Conclusion: COPD subjects had smaller diaphragmatic excursions during maximal respiratory efforts than control subjects. During maximal respiratory efforts in COPD patients, diaphragm excursions were well correlated with PEmax. These results suggest that diaphragm excursions during maximal respiratory efforts with COPD patients may be valuable at predicting the pulmonary function.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.157-168
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• 2008

Statement of problem: Over the past two decades, implant supported fixed prosthesis have been widely used. However, there are few studies conducted systematically and intensively on the splinting effect of implant systems in mandible. Purpose: The purpose of this study was to investigate the changes in stress distributions in the mandibular implants with splinting or non-splinting crowns by performing finite element analysis. Materials and methods: Cortical and cancellous bone were modeled as homogeneous, transversely isotropic, linearly elastic. Perfect bonding was assumed at all interfaces. Implant models were classified as follows. Group 1: $Br{{\aa}}nemark$ length 8.5mm 13mm splinting type Group 2: $Br{{\aa}}nemark$ length 8.5mm 13mm Non-splinting type Group 3: ITI length 8.5mm 13mm splinting type Group 4: ITI length 8.5mm 13mm Non-splinting type An load of 100N was applied vertically and horizontally. Stress levels were calculated using von Mises stresses values. Results: 1. The stress distribution and maximum von Mises stress of two-length implants (8.5mm, 13mm) was similar. 2. The stress of vertical load concentrated on mesial side of implant while the stress of horizontal load was distributed on both side of implant. 3. Stress of internal connection type was spreading through abutment screw but the stress of external connection type was concentrated on cortical bone level. 4. Degree of stress reduction was higher in the external connection type than in the internal connection type.