• Title/Summary/Keyword: Posterior distribution

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A Study of Energy Dependency in Intensity Modulated Radiation Therapy of Lung Cancer (폐암환자의 세기조절방사선치료에서 에너지에 따른 선량분포 특성 비교)

  • Kim, Sung-Kyu;Kim, Myung-Se;Yun, Sang-Mo
    • Progress in Medical Physics
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    • v.19 no.3
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    • pp.191-199
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    • 2008
  • PTV considered for the energy, dose distribution exposed to lung and spinal cord, and the characteristic of DVH(Dose Volume Histogram) were compared and investigated by planning the intensity modulated radiation therapy (IMRT) using the photon energies of 6 MV and 10 MV according to tumor location like as the anterior, middle, and posterior regions of lung, and the mediastinum region in lung cancer patients. Our institution installed the linear accelerator (Varian 21 EX-s, USA) equipped with 120 multileaf collimator for lung cancer patients, which is producing the photon energies of 6 MV and 10 MV, and radiation therapy planning was performed with ECLIPSE system (Varian, SomaVision 6.5, USA), which support inverse treatment planning. The tomographic images of 3 mm slice thickness for lung cancer patients were acquired using planning CT, and acquired tomographic images were sent to the Varis system, and then treatment planning was performed in the ECLIPSE system. The radiation treatment planning of the IMRT was processed from various angles according to the regions of the tumor, and using various beam lines according to the size and location of the tumor. The investigation of the characteristic of dose distributions for the energy of 6 MV and 10 MV according to tumor locations in lung cancer patients resulted that the maximum dose of 10 MV energy was 1.2% less than that of 6 MV energy without depending on the tumor location of lung cancer, and the reduction effects of MU were occurred from 10 to 25 MU. Radiation dose exposed to the lung satisfied the less 30% of V20, however radiation dose in 6 MV energy was from 0.1% to 0.5% less than that in 10 MV energy. Radiation dose exposed to the spinal cord for 6 MV energy was from 0.6% to 2.1% less than that for 6 MV energy.

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A STUDY ON THE MAXIMUM BITE FORCE AND FACIAL MORPHOLOGY ACCORDING TO CHEWING SIDE PREFERENCE (저작습관에 따른 교합력과 안면골격형태의 비교연구)

  • Jeong, Mi-Ra;Son, Woo-Sung
    • The korean journal of orthodontics
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    • v.25 no.3 s.50
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    • pp.311-321
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    • 1995
  • This study was undertaken to investigate the distribution of the chewing side preference and variations in the maximum bite force and facial morphology according to chewing side preference since unilateral chewing may cause morphologic and functional anomalies. 50 dental students who had no signs or symptoms of masticatory system and Angle's Class I relationship in posterior segments were selected, and divided into two groups, that is, 25 in bilateral chewing group(19 male and 6 female) and 25 in unilateral chewing group(10 male and 15 female). Maximum bite force was estimated ana posteroanterior cephalogram were measured ana statistically analyzed. The results were as follows : 1. Their were more students with bilateral chewing side preference($68\%$) and unilateral chewing side group consisted of right side preference($68\%$) and left side preference($32\%$). 2. There was no significant difference in the strength of max. bite force between the right and left side in bilateral chewing group. The bite force of the chewing side nab greater in the unilateral chewing group but less in the non-chewing side compared to those of bilateral chewing group with Bo significant difference. Max. bite force of chewing side was greater than that of non-chewing side in the unilateral chewing group(Female p<0.05). Max. bite force of males was about twice in that of females in both groups(p<0.05). Max. bite force of chewing side of the unilateral chewing group was similar to that of the bilateral chewing group, but that of non-chewing side was less than that of the bilateral chewing group. 3. In comparison of the facial morphology, there was no statistically significant difference in the size between the right and left side of the bilateral chewing group and between chewing and non-chewing side of the unilateral chewing group.

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Classification of Congenital Urinary Tract Anomalies Diagnosed by Antenatal Ultrasonogram (산전 초음파로 발견된 선천성 요로계 기형의 분류)

  • Choi Jin-Ho;Hahn Hye-Won;Won Hye-Sung;Kim Kun-Suk;Yoon Chong-Hyun;Park Young-Seo
    • Childhood Kidney Diseases
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    • v.6 no.2
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    • pp.227-236
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    • 2002
  • Purpose : A study was done to assess the incidence and classification of congenital urinary tract anomalies detected by antenatal ultrasonogram. Methods : We reviewed 558 cases of urinary tract anomaly which were detected by antenatal ultrasonogram and postnatally confirmed between June 1989 and May 2002. We investigated the incidence and classified congenital urinary tract anomalies by review of medical records, antenatal and postnatal radiologic studies retrospectively. Results : In 558 cases of congenital urinary tract anomalies, 292 cases of hydronephrosis were found and the most common. Another anomalies were composed of 65 cases of multicystic dysplastic kidney, 32 cases of hydroureteronephrosis, 31 cases of duplication of kidney, 25 cases of renal agenesis, 21 cases of simple renal cyst, 20 cases of polycystic disease, 13 cases of ureterocele, 11 cases of renal hypoplasia, 10 cases of horseshoe kidney, 9 cases of vesicoureteral reflux, 8 cases of posterior urethral valve, 7 cases of bladder diverticulum, 6 casts of megaureter, 5 cases of ectopia, 2 cases of megacystis, and 1 case of medullary cystic disease. In 82 of the 558 cases, there were two or more combined urinary tract anomalies. Associated diseases other than urinary tract were observed in 13 cases, of which the congenital heart disease was the most common. Conclusion : The congenital urinary tract anomaly is frequently found and diverse during the antenatal ultrasonography. The multicenter study is needed to investigate precise incidence and distribution of each anomalies in general population.

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Clinical Study on Primary Mediastinal Tumors and Cysts -Report of 344 Cases- (원발성 종격동 종양 및 낭종에 대한 임상적 고찰 -344예에 대한 보고-)

  • Lee, Hong-Lyeol;Kim, Se-Kyu;Kim, Hae-Kyun;Chung, Kyung-Young;Lee, Doo-Yun;Kim, Sung-Eun;Chang, Joon;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.5
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    • pp.575-583
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    • 1993
  • Background: Mediastinal masses are not uncommon, and an overall incidence of one case per 100,000 population per year in individuals of all ages and with no difference in sex incidence may be a reasonable estimation. At least half of all mediastinal masses are asymptomatic and this proportion has increased in recent decades with wider use of screening chest roentgenography. Symptoms in patients with mediastinal mass lesions are usually due to compression or invasion of nearby intrathoracic structures. Most mediastinal mass lesions have characteristic predilectional locations. The basic focus of diagnostic evaluation is an orderly preparation for obtaining a tissue diagnosis but even lesions discovered to be benign must generally be removed. Seldom is this status known for certain preoperatively. In additaion, benign tumors may continue to enlarge, thus compromising vital organs; they may rupture, hemorrhage, become infected or have the possibility of various malignant degeneration. Therefore, all mediastinal masses must be surgically removed whether they are malignant or benign. Methods: We reviewed the medical records of 344 cases previously confirmed as mediastinal tumors or cysts from January, 1960 to August, 1992 and investigated the clinical findings. Results: Neurogenic tumors were the most common(24.7%) and thymomas were distinctively increased recently. Overall ratio between males and females was 1.1:1 and age distribution was relatively even among all age groups. Predilectional sites were posterior for neurogenic tumors, and anterior for teratodermoid tumors, thymomas and lymphomas. Dyspnea was the most common symptom in the patients of the mediastinal tumors and asymptomatic patients were 19.5%, Benign mediastinal mass lesions were 66.0% and malignant, 34.0%, Complete or partial resection was done in 42.4%. Conclusion: We could find the increasing incidence and the tendency of aggressive resection as possible in the mediastinal tumors. We expect the discovery of more mediastinal tumors with wider use of regular check-up and development of diagnostic methods.

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Comparison of rCBF between Patients with Medial Temporal Lobe Epilepsy and Normal Controls using ${H_2}^{15}O\;PET$ (내측 측두엽 간질환자와 정상인의 ${H_2}^{15}O\;PET$을 이용한 뇌 혈류량 비교)

  • Kang, Eun-Joo;Lee, Jae-Sung;Nam, Hyun-Woo;Lee, Sang-Kun;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.3
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    • pp.155-165
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    • 2002
  • Purpose: The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using ${H_2}^{15}O-PET$. Materials and Methods: 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was peformed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Results: During the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal legions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal legions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Conclusion: Epilepsy induced changes were found not only in relative increase/decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period.

A STUDY OF INTRAORAL ANATOMIC LANDMARKS OF KOREAN ADULT-UPPER JAW (성인 유치악자 상악골의 악궁과 치열궁의 형태에 관한 조사)

  • Oh, Yu-Ree;Lee, Sung-Bok;Park, Nam-Soo;Choi, Dae-Gyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.33 no.4
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    • pp.753-768
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    • 1995
  • For accurate impression taking of dental patient and esthetic denture treatment of ednetulous patient, measuring between intraoral anatomic landmarks is useful.In this study the subjects selected at a random were two-jundred forty persons with a mean age 22.5(range 21-24) and were taken impression of by irreversible hydrocolloid impression material(Alginate). On the study model made by dental stone, each individual tray was made and final impresion was taken by border moilding. On final model measurings were performed with 3-dimensional measuring device and the values were analyzed by t-test The results is following : ABOUT THE MEASURED VALUES. 1. The width between maxillary right and left canine cusp tip was average 36.44mm(s.d. 2.48), man 36.67mm, woman 35.83mm(p<0.05). 2. The width between labial height of contour of maxillary right and left canine was average 40.08mm(s.d. 2.42), man 40.29mm, woman 39.52mm(p<0.05). 3. The width between mesio-lingual cusps of maxillary first molar was average 43.14mm(s.d. 3.33), man 43.56mm, woman 42.05mm(p<0.05). 4. The width between buccal alveolar ridge on axis of mesiolingual cusp of right and left maxillary first molar was average 64.89mm(s.d. 3.88), man 65.58mm, woman 62.92mm(p<0.05). 5. The width between buccal alveolar ridge on axis of mesiolingual cusp of right and left maxillary second molar was average 68.58mm(s.d. 3.91), man 69.29mm, woman 66.30mm (p<0.05). 6. The width between right and left hamular notch was average 49.80mm(s.d. 3.96), man 50.70mm, woman 48.20mm(p<0.05). 7. The length from labial heigth of contour of maxillary central incisor to center of incisive papilla was average 9.52mm(s.d. 1.18), man 9.46mm, woman 9.63mm(p>0.05). 8. The length from labial heigth of contour of maxillary central incisor to palatine fovea was average 53.27mm(s.d. 2.93), man 53.93mm, woman 52.08mm(p<0.05). 9. The center of incisive papilla ws located posterior to intercanine line at 0.40mm(s.d. 1.16), man 0.51mm, woman 0.11mm(p<0.05). 10. The height from incisal edge of maxillary central incisor to the labial vestibule was average 21.84mm(s.d. 1.38), man 22.01mm, woman 21.00mm(p<0.05). 11. The height from mesiolingual cusp of maxillary first molar to buccalvestible was average 17.45mm(s.d. 1.42), man 17.56mm, woman 17.08mm(p>0.05). 12. The height from hamular notch to standard occlusal plane was average 6.84mm(s.d. 1.06), man 6.91mm, woman 6.70mm(p>0.05). 13. The height from the deepest point of palatal vault to standard occlsalplane was average 19.95 mm(s.d. 2.03), man 20.19mm, woman 19.12mm(p<0.05). ABOUT THE ARCH FORM 1. The arch form was able to classify into four typr by the rate of the measured values. Each arch form distribution was that the 1 group had 32.46% the 2 group 2.19%, the 3 group 52.83%, the 4 group 12.72%. The sexual composition was that in 1 group man had 73.5%, woman 26.5%, in 2 group man had 40.0%, woman 60.0%, in 3 group man had 83.3%, woman 16.7%, and in 4 group man had 55.17%, woman 44.83%. 2. When canine cusp tip was marked as point O, the intersection point between labial height of contour of maxillary central incisor and intermaxillary suture as point A, height of contour of maxillary second molar buccal alveolar ridge as B point, ${\angle}$AOB was measured $133.8^{\circ}$for the 1 group, $133.0^{\circ}$for the 2 group, $132.3^{\circ}$for the 3 group, $128.9^{\circ}$for the 4 group.

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The Comparison of DVH between Multiple arc FSRT and Conformal FSRT (Multiple arc FSRT와 Conformal FSRT의 DVH 비교)

  • Kim Ki-Hwan;Kim Jun-Sang;Jang JiYoung;Kim Jae-Sung;Kim Seong-Ho;Song Chang-Joon;Park Min-Kyu;Cho Moon-June
    • Radiation Oncology Journal
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    • v.17 no.3
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    • pp.261-267
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    • 1999
  • Purpose : In FSRT (Fractionated stereotactic radiotherapy) planning, we studied the usefulness between multiple arc FSRT and conformal FSRT by comparing tumor shape and DVH (dose volume histogram). Materials and Methods In Chungnam Univ. hospital, we had treated the sixteen patients with FSRT from Aug. 1997 to Dec. 1998. In choosing multiple arc FSRT or conformal FSRT, we had considered If (irregular factor) after calculating tumor volume and surface area. We had considered multiple arc FSRT if tumor shape was similar to sphere or the value of If was less than 1.25, conformal FSRT if tumor shape was very irregular or If was more than 1.3. For evaluation of treatment planning, we had considered the appropriate DVH for tumor volume and for critical organs. Results : The errors between reference point and the coordinates point on AP, Lat radiography were less than 1 mm before treatment. We had planned $3\~$5 arcs for multiple arc FSRT, $5\~6$ports for conformal FSRT. The mean dose distribution of tumor volume of cumulative DVH between multiple arc FSRT and conformal FSRT was 90.6, 85%, respectively. The dose of critical organs irradiated was less than $5\%$ maximum dose of cumulative DVH. Conclusion : We had obtained the similar value between multiple arc FSRT and conformal FSRT, so that we had appropriate treatment planning of FSRT for multiple arc FSRT and conformal FSRT according to tumor shape and size.

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Studies on the Reproductive Cycle of Damselfish, Chromis notatus (Temminck et Schlegel) (자리돔의 생식주기에 관한 연구)

  • LEE Young Don;LEE Taek Yuil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.6
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    • pp.509-519
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    • 1987
  • Annual reproductive cycle of the Damselfish, Chromis notatus collected monthly at the four coastal areas around Chejudo, Korea are studied on the bases of histological observations of gonadal tissue and various quantitative variables including gonadosomatic index (GSI), fatness, egg diameter composition and the first maturity. The ovary consisted of a pair of saccular structure with many ovarian sacs. Oogonia proliferated along the germinal epithelium of the ovarian sac. Young oocytes with basophilic cytoplasm showed several nucleoli along the nuclear membrane. When the oocytes reached about $450{\mu}m$ in diameter, nucleus migrate toward the animal pole, nuclear membrane disappeared and most of cytoplasm were filled with yolk materials and oil drops. After ovulation, residual follicle and growing oocytes remaining in the ovarian sacs degenerated. But early young oocytes without follicle layer were not degenerated, and growing continuously till the next year. The testis consisted of a pair of lobular structures in the right and left were united in the posterior seminal vesicle. Cortex of testis was composed of many sperm ducts connected with lobuli. GSI began to increase from March, starting season of longer day length and higher water temperature, and reached the maximum value between June and August. It began to decrease from September with the lowest value appearing between October and February without any evident variation. The annual reproductive cycle could be devided into five successive stage : growing(April to Many), mature(May to August), ripe and spent (June to August) and recovery and resting stage(September to March). The spawning peak occurred from June to August. According to the frequency distribution of egg diameter, Chromis notatus was a polycyclic species to spawn twice or more in a spawning season. Fatness, correlated with gonadal phases, was remarkably decreased by spawning. Percentage of the first maturity . in femate and male fish ranging from 7.0 to 7.9 cm were $50\%$ and from 9.0 to 9.9 cm in total length $100\%$.

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Stress distribution following face mask application using different finite element models according to Hounsfield unit values in CT images (CT상의 HU 수치에 따른 상악골 전방견인 효과의 유한요소 분석)

  • Chung, Dong-Hwa
    • The korean journal of orthodontics
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    • v.36 no.6
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    • pp.412-421
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    • 2006
  • Objective: The result of finite element analysis depends on material properties, structural expression, density of element, and boundar or loading conditions. To represent proper elastic behavior, a finite element model was made using Hounsfield unit (HU) values in CT images. Methods: A 13 year 6 month old male was used as the subject. A 3 dimensional visualizing program, Mimics, was used to build a 3D object from the DICOM file which was acquired from the CT images. Model 1 was established by giving 24 material properties according to HU. Model 2 was constructed by the conventional method which provides 2 material properties. Protraction force of 500g was applied at a 45 degree downward angle from Frankfort horizontal (FH) plane. Results: Model 1 showed a more flexible response on the first premolar region which had more forward and downward movement of the maxillary anterior segment. Maxilla was bent on the sagittal plane and frontal plane. Model 2 revealed less movement in all directions. It moved downward on the anterior part and upward on the posterior part, which is clockwise rotation of the maxilla. Conclusion: These results signify that different outcomes of finite element analysis can occur according to the given material properties and it is recommended to use HU values for more accurate results.

Clinical Assessment, Panoramic and MRI Findings and Cephalometric Characteristics of Patients with Condylar Resorption (과두흡수환자의 자기공명영상 사진 평가 및 악안면 골격형태에 대한 연구)

  • Jang, Heon-Su;Hur, Yun-Kyung;Kim, Kyun-Yo;Ko, Yu-Jeong;Chae, Jong-Moon;Choi, Jae-Kap
    • Journal of Oral Medicine and Pain
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    • v.34 no.4
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    • pp.409-420
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    • 2009
  • The aim of this study was to investigate clinical assessment, panorama & MRI findings and cephalometric characteristics in 42 patients with condylar resorption, who visited in the Department of Oral Medicine Kyungpook National University Hospital at 2006. The results were as follows; 1. Clinical assessment 1) Female was 34 and male was 8, females were predominant. Distribution of age showed as follows; 10s was 14, 20s was 13, 30s was 7, 40s was 3, 50s was 4 and 60s was 1 patient. 10s and 20s were predominant. 2) Most of the patients had parafunctional habit. 2. Findings of panorama & MRI 1) Most of the patients had degree of Grade II condylar resorption by panorama taking. 2) Most of the patients had disc dislocation and belonged to the degree of stage IV by MRI taking. 3. Cephalometric Characteristics 1) SN, SAr and saddle angle in female patients were significantly smaller and SN in male patients showed only significantly smaller than normal group. 2) SNA showed no difference from the normal group in both patients. SNB was smaller and ANB was lager in female patients than normal group. 3) SN-GoMe and FMA increased in patients. 4) Total posterior facial height & ramus height were significantly smaller. 5) Mandibular body length did not show any significant difference.