• Title/Summary/Keyword: computed tomography(CT)

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SINUS FLOOR GRAFTING USING CALCIUM PHOSPHATE NANO-CRYSTAL COATED XENOGENIC BONE AND AUTOLOGOUS BONE (칼슘포스페이트 나노-크리스탈이 코팅된 골이식재와 자가골을 병행 이용한 상악동 거상술)

  • Pang, Kang-Mi;Li, Bo-Han;Alrashidan, Mohamed;Yoo, Sang-Bae;Sung, Mi-Ae;Kim, Soung-Min;Jahng, Jeong-Won;Kim, Myung-Jin;Ko, Jea-Seung;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.3
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    • pp.243-248
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    • 2009
  • Purpose: Rehabilitation of the edentulous posterior maxilla with dental implants often poses difficulty because of insufficient bone volume caused by pneumatization of the maxillary sinus and by crestal bone resorption. Sinus grafting technique was developed to increase the vertical height to overcome this problem. The present study was designed to evaluate the sinus floor augmentation with anorganic bovine bone (Bio-$cera^{TM}$) using histomorphometric and clinical measures. Patients and methods: Thirteen patients were involved in this study and underwent total 14 sinus lift procedures. Residual bone height was ${\geq}2mm$ and ${\leq}6mm$. Lateral window approach was used, with grafting using Bio-$cera^{TM}$ only(n=1) or mixed with autogenous bone from ramus and/or maxillary tuberosity(n=13). After 6 months of healing, implant sites were created with 3mm diameter trephine and biopsies taken for histomorphometric analysis. The parameters assessed were area fraction of new bone, graft material and connective tissue. Immediate and 6 months after grafting surgery, and 6 months after implantation, computed tomography (CT) was taken and the sinus graft was evaluated morphometric analysis. After implant installation at the grafted area, the clinical outcome was checked. Results: Histomorphometry was done in ten patients.Bio-$cera^{TM}$ particles were surrounded by newly formed bone. The graft particles and newly formed bone were surrounded by connective tissue including small capillaries in some fields. Imaging processing revealed $24.86{\pm}7.59%$ of new bone, $38.20{\pm}13.19%$ connective tissue, and $36.92{\pm}14.51%$ of remaining Bio-$cera^{TM}$ particles. All grafted sites received an implant, and in all cases sufficient bone height was achieved to install implants. The increase in ridge height was about $15.9{\pm}1.8mm$ immediately after operation (from 13mm to 19mm). After 6 months operation, ridge height was reduced about $11.5{\pm}13.5%$. After implant installation, average marginal bone loss after 6 months was $0.3{\pm}0.15mm$. Conclusion: Bio-$cera^{TM}$ showed new bone formation similar with Bio-$Oss^{(R)}$ histomorphometrically and appeared to be an effective bone substitute in maxillary sinus augmentation procedure with the residual bone height from 2 to 6mm.

Dosimetric effects of couch attenuation and air gaps on prone breast radiation therapy (Prone Breast Phantom을 이용한 couch 산란영향 평가)

  • Kim, Min Seok;Jeon, Soo Dong;Bae, Sun Myeong;Baek, Geum Mun;Song, Heung Gwon
    • The Journal of Korean Society for Radiation Therapy
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    • v.29 no.2
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    • pp.43-51
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    • 2017
  • Purpose: The purpose of this study is to evaluate the dosimetric effects of couch attenuation and air gaps using 3D phantom for prone breast radiation therapy. Materials and method: A 3D printer(Builder Extreme 1000) and computed tomography (CT) images of a breast cancer patient were used to manufacture the customized breast phantom. Eclipse External Beam Planning 13.6 (Varian Medical Systems Palo Alto, CA, USA) was used to create the treatment plan with a dose of 200 cGy per fraction with 6 MV energy. The Optically Stimulated Luminescence Detector(OSLD) was used to measure the skin dose at four points (Med 1, Med 2, Lat 1, Lat 2) on the 3D phantom and ion-chamber (FC65-G) were used to perform the in-vivo dosimetry at the two points (Anterior, Posterior). The Skin dose and in-vivo dosimetry were measured with reference air gap (3 cm) and increased air gaps (1, 2, 3, 4, 5, 6 cm) from reference distance between the couch and 3D phantom. Results: As a result, measurement for the skin dose at lateral point showed a similar value within ${\pm}4%$ compared to the plan. While the air gap increased, skin dose at medial 1 was reduced. And it was also reduced over 7 % when the air gap was more than 3 cm compared to radiation therapy plan. At medial 2 it was reduced over 4 % as well. The changes of dose from variety of the air gap showed similar value within ${\pm}1%$ at posterior. As the air gap was increased, the dose at anterior was also increased and it was increased by 1 % from the air gap distance more than 3 cm. Conclusion: Dosimetrical measurement using 3D phantom is very useful to evaluate the dosimetric effects of couch attenuation and air gaps for prone breast radiation therapy. And it is possible to reduce the skin dose and increase the accuracy of the radiation dose delivery by appling the optimized air gap.

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Changes of lip morphology following mandibular setback surgery using 3D cone-beam computed tomography images

  • Paek, Seung Jae;Yoo, Ji Yong;Lee, Jang Won;Park, Won-Jong;Chee, Young Deok;Choi, Moon Gi;Choi, Eun Joo;Kwon, Kyung-Hwan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.38
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    • pp.38.1-38.10
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    • 2016
  • Background: The aims of this study are to evaluate the lip morphology and change of lip commissure after mandibular setback surgery (MSS) for class III patients and analyze association between the amount of mandibular setback and change of lip morphology. Methods: The samples consisted of 14 class III patients treated with MSS using bilateral sagittal split ramus osteotomy. Lateral cephalogram and cone-beam CT were taken before and about 6 months after MSS. Changes in landmarks and variables were measured with 3D software program $Ondemand^{TM}$. Paired and independent t tests were performed for statistical analysis. Results: Landmarks in the mouth corner (cheilion, Ch) moved backward and downward (p < .005, p < .01). However, cheilion width was not statistically significantly changed. Landmark in labrale superius (Ls) was not altered significantly. Upper lip prominence angle (ChRt-Ls-$ChLt^{\circ}$) became acute. Landmarks in stomion (Stm), labrale inferius (Li) moved backward (p < .005, p < .001). Lower lip prominence angle (ChRt-Li-$ChLt^{\circ}$) became obtuse (p < .001). Height of the upper and lower lips was not altered significantly. Length of the upper lip vermilion was increased (p =< 0.01), and length of the lower lip vermilion was decreased (p < .05). Lip area on frontal view was not statistically significantly changed, but the upper lip area on lateral view was increased and change of the lower lip area decreased (p > .05, p < .005). On lateral view, upper lip prominent point (UP) moved downward and stomion moved backward and upward and the angle of Ls-UP-Stm ($^{\circ}$) was decreased. Lower lip prominent point (LP) moved backward and downward, and the angle of Stm-LP-Li ($^{\circ}$) was increased. Li moved backward. Finally, landmarks in the lower incisor tip (L1) moved backward and upward, but stomion moved downward. After surgery, lower incisor tip (L1) was positioned more superiorly than stomion (p < .05). There were significant associations between horizontal soft tissue and corresponding hard tissue. The posterior movement of L1 was related to statistically significantly about backward and downward movement of cheilion. Conclusions: The lip morphology of patients with dento-skeletal class III malocclusion shows a significant improvement after orthognathic surgery. Three-dimensional lip morphology changes in class III patients after MSS exhibited that cheilion moved backward and downward, upper lip projection angle became acute, lower lip projection angle became obtuse, change of upper lip area on lateral view was increased, change of lower lip area decreased, and morphology of lower lip was protruding. L1 was concerned with the lip tissue change in statistically significant way.

The Predcitors of the Development of Acute Respiratory Distress Syndrome in the Patients with Acute Pancreatitis (급성 췌장염으로 내과계 중환자실에 입원한 환자들의 급성호흡곤란 증후군 발생에 연관된 인자에 관한 연구)

  • Yoo, Mi-Ran;Koh, Youn-Suck;Lim, Chae-Man;Lee, Moon-Gyu;Lee, Hong-Jae;Lee, Moo-Song;An, Jong-Jun;Lee, Sung-Koo;Kim, Myung-Hwan;Lee, Sang-Do;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.4
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    • pp.861-870
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    • 1997
  • Background : Though acute respiratory distress(ARDS) often occurs in the early stage of severe acute pancreatitis and significantly contributed to the mortality of the condition, the characteristics of the group who develops ARDS in the patients with acute pancreatitis have not been fully found. The objective of this investigation was to identify predictable factors which distinguish a group who would develop ARDS in the patients with acute pancreatitis. Method : A retrospective analysis of 94 cases in 86 patients who were admitted the Medical Intensive Care Unit with acute pancreatitis was done. ARDS were developed in 13 cases among them (13.8%). The possible clinical factors related to the development were analyzed using univariate analysis and $x^2$-test. Results : The risk of ARDS development was increased in the patients with abonormal findings of chest X-ray at admission compared to the patients with normal chest X-ray (p<0.05). The risk was also increased according to the sevecrity index score in abdominal computed tomography at the time of admission (p<0.05). The higher APACHE III score of the first day of admission, the more risk increment of ARDS development was observed (p<0.01). Patients with more than one points of Murray's lung injury score showed higher risk of ARDS compared to the patients with 0 points of that. The patients with sepsis and the patients with more than three organ dysfunction at admission had 3.5 times and 23.3 times higher risk of the development of ARDS compared to the patients without sepsis and without organ failure in each (p<0.05, p<0.01). Conclusion : The risk of ARDS development would be higher in the acute pancreatitis patients with abnormal chest X-ray, higher CT severity index, higher APACHE III or Murray's lung injury score, accompanying sepsis, and more than three organ failure at admission.

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Evaluation of the Treatment Response after Hypofractionated Radiotherapy in Patients with Advanced Head and Neck Cancers (진행성 두경부 상피세포암 환자에서 소분할 방사선조사 후의 치료반응 평가)

  • Kim, Won-Taek;Ki, Yong-Kan;Nam, Ji-Ho;Kim, Dong-Hyun;Cho, Kyu-Sup;Lee, Jin-Choon;Lee, Byung-Joo;Kim, Dong-Won
    • Radiation Oncology Journal
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    • v.27 no.2
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    • pp.55-63
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    • 2009
  • Purpose: This study was performed to objectively evaluate the rate of tumor response to hypofractionated radiotherapy for advanced squamous cell carcinomas of the head and neck. Materials and Methods: Thirty-one patients with advanced squamous cell carcinoma of the head and neck, who were treated by hypofractionated radiotherapy with 3 Gy per fraction for palliative purpose between 1998 and 2008, were reviewed retrospectively. Every tumor-volume was measured and evaluated from CT (computed tomography) images obtained before and 2~3 months after radiotherapy. The radiation toxicity was assessed during and after radiotherapy. A statistical analysis was performed to investigate overall survival, progressionfree survival, and the prognostic factors for survival and response. Results: The median age of the study patients was 70 years. In addition, 85% of the patients were in stage 4 cancer and 66.7% had an ECOG performance status of 1~2. The mean tumor-volume was 128.4 cc. Radiotherapy was administered with a total dose of 24~45 Gy (median: 36 Gy) over 10~25 days. Twenty-nine patients were treated with 30 Gy or more. The observed complete response rate was 12.9% and the partial response rate was 61.3%. Median survival time was 8.9 months and the 1-year progression-free survival rate was 12.9%. The treatment response rate was confirmed as a prognostic factor in the rate of survival. The primary site, stage, tumor-volume, radiotherapy field and overall radiation-dose showed a significant relationship with survival and treatment response. No grade 4 toxicity was observed during and after radiotherapy. Conclusion: There was an objective tumor-regression in about 74% of patients treated by hypofractionated radiotherapy. Further evaluation is needed to select the appropriate fraction-size and patient who may require the additional radiotherapy.

Usefulness of modified ambu® in patients who need artificial ventilation (인공 환기가 필요한 환자에서 변형된 수동식 인공호흡기(Ambu®)의 유용성)

  • Ha, Kee Soo;Moon, Il Hong;Lee, Hee Sun;Shin, Dong Han;Eun, So Hee;Eun, Baik-Lin;Hong, Young Sook;Lee, Joo Won
    • Clinical and Experimental Pediatrics
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    • v.49 no.11
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    • pp.1194-1201
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    • 2006
  • Purpose : The comatose mentality can be catastrophic, especially if the condition is severe or the duration is prolonged. Therefore, delayed diagnosis can result in a poor outcome or death. The best radiologic modality to differentiate from cerebral lesions in patients suffering from cerebral diseases is magnetic resonance imaging (MRI) rather than computed tomography (CT). Special apparatuses with metal materials such as ventilators, and cardiac pacemakers belonging to patients cannot be located in the magnetic field. We aimed to exhibit the possibility of examining MRI, maintaining ventilation at a relative long distance by means of modified $Ambu^{(R)}$. Methods : Self-inflating bags as a sort of a manual ventilator, connected with relatively long extension tubes instead of mechanical ventilators, were adopted to obtain MRI. PVC (polyvinyl chloride) extension tubes had different lengths and diameters. Lengths were 1, 2, and 3 cm and diameters were 15, and 25 mm. The work of breathing and expiratory changes of expiratory tidal volume (TVe), minute volume of expiration (MVe), peak inspiratory pressure (PIP) were measured by use of the mechanical ventilator, $Servoi^{(R)}$, as the alteration of TVi (inspiratory tidal volume), extension tube lengths and diameters with other values fixed. Results : Measured TVe and MVe by ventilator were the same values with control at every TVi, regardless of extension tube lengths and diameters, but PIP were increased with the rise of TVi, tube lengths, with decline of tube diameters, these were statistically significant. Conclusion : MRI examination can be carried out with a self-inflating bag connected with an extension tube at a long distance in patients who need artificial ventilation.

Usefulness of Chest High-Resolution CT in Patients with Chronic Cough Below 2 Years of Age (2세 미만의 만성 기침 환아에서 흉부 고해상 전산화 단층 촬영의 유용성)

  • Kim, Myung Hyun;Kim, Jung Hee;Lim, Dae Hyun;Son, Byong Kwan;Lee, Kyung-Hee
    • Clinical and Experimental Pediatrics
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    • v.45 no.3
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    • pp.339-345
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    • 2002
  • Purpose : The purpose of this study was to evaluate the clinical usefulness of chest high-resolution computed tomography(HRCT) in patients with chronic coughs or persistent wheezing with normal chest X-ray finding. Methods : We reviewed the charts, chest X-rays, and HRCT findings of patients with chronic coughs or persistent wheezing of less than 2 years of age. The records were sourced from the Department of Pediatrics, Inha University Hospital covering the period from July, 1999 to June, 2000. Chronic cough was defined as a cough which was prolonged for more than 3 weeks. Results : The sample consisted of 24 patients(male 15 and female 9, mean age $4.7{\pm}3.8$ months old). Among them, 16 patients showed normal findings(66.7%) and 8 patients showed abnormal (33.3%) in simple chest X-rays. Among 16 patients who had the normal chest X-rays, 13 patients showed abnormal chest HRCT findings(81.3%) such as air space consolidation of the dependent portion(62.5%), bronchiolitis obliterans(12.5%), and bronchopulmonary dysplasia(6.3%). Conclusion : We suggest that the chest HRCT is a useful diagnostic tool in the evaluation of patients with chronic cough or persistent wheezing with normal chest X-ray, especially below 2 years of age.

A Study on Prospective Plan Comparison using DVH-index in Tomotherapy Planning (토모 테라피 치료 시 선량 체적 히스토그램 표지자를 이용한 치료계획 비교에 관한 연구)

  • Kim, Joo-Ho;Cho, Jeong-Hee;Lee, Sang-Kyoo;Jeon, Byeong-Chul;Yoon, Jong-Won;Kim, Dong-Wook
    • The Journal of Korean Society for Radiation Therapy
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    • v.19 no.2
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    • pp.113-122
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    • 2007
  • Purpose: We proposed the method using dose-volume Histogram index to compare prospective plan trials in tomotherapy planning optimization. Materials and Methods: For 3 patients in cranial region, thorax and abdominal region, we acquired computed tomography images with PQ 5000 in each case. Then we delineated target structure and normal organ contour with pinnacle Ver 7.6c, after transferred each data to tomotherapy planning system (hi-art system Ver 2.0), we optimized 3 plan trials in each case that used differ from beam width, pitch, importance. We analyzed 3 plan trials in each region with isodose distribution, dose-volume histogram and dose statistics. Also we verified 3 plan trials with specialized DVH-indexes that is dose homogeneity index in target organ, conformity index around target structure and dose gradient index in non-target structures. Results: We compared with the similarity of results that the one is decide the best plan trial using isodose distribution, dose volume histogram and dose statistics, and the another is using DVH-indexes. They all decided the same plan trial to better result in each case. Conclusion: In some of case, it was appeared a little difference of results that used to DVH-index for comparison of plan trial in tomotherapy by special goal in it. But because DVH-index represented both dose distribution in target structure and high dose risk about normal tissue, it will be reasonable method for comparison of many plan trials before the tomotherapy treatments.

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Stress Patterns in the Reconstructed Double Bundles of the Anterior Cruciate Ligament in Response to an Anterior Tibial Load and Rotatory Load: an Analysis using a 3-Dimensional Finite Element Model (삼차원 유한 요소 모델을 이용한 전방십자인대 이중다발 재건술 후 전방 전위 및 회전 부하에 따른 이식건 응력 양상 분석)

  • Seo, Young-Jin;Song, Si Young;Ahn, Jung Tae;Kim, Yoon-Sang;Ko, Jun Ho;Jang, Seong-Wook;Yoo, Yon-Sik
    • Journal of the Korean Arthroscopy Society
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    • v.16 no.2
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    • pp.160-166
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    • 2012
  • Purpose: The aim of this study was to determine the patterns of the stress distribution within the reconstructed anterior cruciate ligament (ACL) double bundles in response to an anterior tibial load and rotatory load at $45^{\circ}$ flexed knee model by use of a 3-dimensional finite element analysis (FEM). Materials and Methods: The $0^{\circ}$ and $45^{\circ}$ flexed 3-D knee model were reconstructed based on the high resolution computed tomography (CT) images from the right knee of a healthy male subject. To simulate double bundle ACL reconstruction, in $0^{\circ}$ analytic model, four 7 mm diameter tunnels were created at the center of each anteromedial (AM) and posterolateral (PL) footprints on the femur and tibia. The grafts were inserted into the corresponding bone tunnels and then reconstructed knee model was flexed to $45^{\circ}$. As a next step, the 5 mm anterior tibial load and internal rotational load of $10^{\circ}$ were applied on the final Computer aided design (CAD) model. And then stress patterns of each bundle were assessed using a finite element analysis. Results: In response to the 5 mm of anterior tibial load, the AM bundle showed increased stresses around the tibial and femoral attachment sites; especially in the anterior aspect of the bundle. In the PL bundle, the highest stress concentration was also noticed on the anterior aspect of the bundle. Under $10^{\circ}$ internal rotational load, the stress concentration was predominant around the anterior aspect of the tibial attachment site within the AM bundle. The PL bundle also showed highest stress concentration on the anterior aspect of the bundle. Conclusion: Although the stress patterns were not identical among the AM and PL bundle, there were common trends in the stress distribution. The stress concentration was predominant on the anterior aspect of both bundles in response to the anterior tibial load and rotatory load.

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Calculation of Renal Depth by Conjugate-View Method Using Dual-head Gamma Camera (이중 헤드 감마 카메라를 이용한 Conjugate-View 계수법에 의한 신장 깊이 도출)

  • Kim, Hyun-Mi;Suh, Tae-Suk;Choe, Bo-Young;Chung, Yong-An;Kim, Sung-Hoon;Chung, Soo-Kyo;Lee, Hyoung-Koo
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.6
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    • pp.378-388
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    • 2001
  • Purpose: In this study, we developed a new method for the determination of renal depth with anterior and posterior renal scintigrams in a dual-head gamma camera, considering the attenuation factor $e^{-{\mu}x}$ of the conjugate-view method. Material and Method: We developed abdomen and kidney phantoms to perform experiments using Technetium-99m dimercaptosuccinic acid ($^{99m}Tc$-DMSA). The phantom images were obtained by dual-head gamma camera equipped with low-energy, high-resolution, parallel-hole collimators (ICONf, Siemens). The equation was derived from the linear integration of omission ${\gamma}$-ray considering attenuation from the posterior abdomen to the anterior abdomen phantom surface. The program for measurement was developed by Microsoft Visual C++ 6.0. Results : Renal depths of the phantoms were derived from the derived equations and compared with the exact geometrical values. Differences between the measured and the calculated values were the range of 0.1 to 0.7 cm ($0.029{\pm}0.15cm,\;mean{\pm}S.D.$). Conclusion: The present study showed that the use of the derived equations for renal depth measurements, combined with quantitative planar imaging using dual-head gamma camera, could provide more accurate results for individual variation than the conventional method.

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