• Title/Summary/Keyword: medial axis

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A Study on Automatic Modeling of Pipelines Connection Using Point Cloud (포인트 클라우드를 이용한 파이프라인 연결 자동 모델링에 관한 연구)

  • Lee, Jae Won;Patil, Ashok Kumar;Holi, Pavitra;Chai, Young Ho
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.3
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    • pp.341-352
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    • 2016
  • Manual 3D pipeline modeling from LiDAR scanned point cloud data is laborious and time-consuming process. This paper presents a method to extract the pipe, elbow and branch information which is essential to the automatic modeling of the pipeline connection. The pipe geometry is estimated from the point cloud data through the Hough transform and the elbow position is calculated by the medial axis intersection for assembling the nearest pair of pipes. The branch is also created for a pair of pipe segments by estimating the virtual points on one pipe segment and checking for any feasible intersection with the other pipe's endpoint within the pre-defined range of distance. As a result of the automatic modeling, a complete 3D pipeline model is generated by connecting the extracted information of pipes, elbows and branches.

Contribution of Genetic and Neuroimaging Studies towards a Better Understanding of Post-Traumatic Stress Disorder (외상 후 스트레스 장애의 이해에 있어서 유전학 및 뇌영상 연구의 기여)

  • Kim, Ji-Eun E.;Lyoo, In-Kyoon;Jun, Chan-Soo;Lee, Yu-Sang
    • Korean Journal of Biological Psychiatry
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    • v.17 no.4
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    • pp.177-193
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    • 2010
  • Significant advances have been made in understanding the biological underpinnings of post-traumatic stress disorder(PTSD), particularly in the field of genetics and neuroimaging. Association studies in candidate genes related with hypothalamic-pituitary-adrenal axis, monoamines including serotonin, dopamine and noradrenaline, and proteins including FK506-binding protein 5 and brain-derived neurotrophic factor have provided important insights with regard to the vulnerability factors in PTSD. Genome-wide association studies and epigenetic studies may provide further information for the role of genes in the pathophysiology of PTSD. Hippocampus, medial prefrontal cortex, anterior cingulated cortex and amygdala have been considered as key structures that underlie PTSD pathophysiology. Future research that combines genetic and neuroimaging information may provide an opportunity for a more comprehensive understanding of PTSD.

마우스 골재생모델의 제작방법 검토와 골질(bone quality) 및 골양(bone quantity) 파라미터의 해석

  • Lee, Ji-Uk;Kawahara, Keita;Nakano, Takayoshi;Kim, Seung-Eon;Yun, Hui-Suk
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.44.1-44.1
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    • 2009
  • 최근 경조직 재생 (hard tissue regeneration) 에 대한 연구가 활발히 진행되고 있다. 그러나 이와같은 연구는 결손도입의 어려움 및 이차적인 골절의 위험성 때문에 대형동물을 중심으로 진행되고 있으며, 그 결과 동물실험에 있어서 시간적 경제적으로 큰 리스크를 수반한다. 그러나 유전자 변형동물의 대부분은 마우스이며, 분자생물학적 관점에서 골재생의 과정을 이해하기 위해서는 마우스를 이용한 골재생 모델의 확립이 필요하다. 따라서 본 연구에서는 마우스를 통해 경조직 재생모델의 제작방법을 검토함과 동시에, 골재생부위에 대한 골질 (bone quality) 및 골양 (bone quantity) 평가의 방법을 수립하는 것을 목적으로 하였다. 골결손은 생후 8주의 마우스에 시술하였다. 치과용 드릴을 이용하여 경골 (tibia) 길이의 30 % 부근의 내측(medial) 면에서 골수강 (marrow cavity) 방향으로 $500\;{\mu}m\varphi$의 원주형 결손을 도입하였다. 시술 후의 골재생과정을 관찰하기 위해 ${\mu}CT$ (SMX-100CT: Simazu) 를 이용하여 주기적으로 촬영하였으며, 골양 (BV/TV) 의 회복과정은3D-bon (RATOC) 을 이용하여 정량적인 해석을 수행하였다. 그리고 재생부의 골질 (아파타이트 배행성; BAp orientation) 평가는 투과형micro-beam XRD (R-AXIS BQ: Rigaku)를 이용하여 수행하였다.

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Radiographic and Ultrasonographic Diagnosis of Single Intrahepatic Portosystemic Shunt in a Dog (개의 단순 간내성 간문맥전신단락증의 영상진단학 및 치료 1예)

  • 전혜영;장동우
    • Journal of Veterinary Clinics
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    • v.20 no.4
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    • pp.508-515
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    • 2003
  • A 4-month-old 5.7 kg male Golden retriever with history of seizure, depression, lethargy and anorexia was referred to Veterinary Medical Teaching Hospital, Chungbuk National University. Hematologic examination revealed microcytosis and nonregenerative anemia. Serum chemical values showed increased serum ammonia (423 $\mu$mol/L), ALP (1101 U/L), r-GTP (13.9 U/L) and CPK (1454 U/L), and decreased total protein (4.9 g/dl) and BUN (1.6 mg/dl). Microhepatia was shown in survey abdominal radiographs. Color doppler ultrasonographic examination revealed dilated tortuous vein with turbulent flow within liver parenchyma. Intraoperative jejunoportography and intraoperative ultrasonography confirmed the location and size of single intrahepatic shunt vessel in the left medial liver lobe. Also, the anomalous vessel entering the caudal vena cava was identified beneath the diaphragm. The shunting vessel was ligated with using an Ameroid constrictor. General conditions, hematologic and serum chemical values resolved gradually after surgery. One month after surgery abdominal radiograph showed normal gastric axis and it was consistent whit the normal size liver. Normal echogenecity of liver and enlargement of portal vein were shown in ultrasonography. It is assumed that survey radiography and ultrasonography are useful for diagnosis of single intrahepatic shunt in a dog and especially jejunoportography vein portography and intraoperative ultrasonography are suitable for confirmation of the anatomic location and size of the shunting vessels.

Anatomical Study for Vascular Distribution of the Perforator of Deep Inferior Epigastric Artery in Koreans (한국인에 있어 깊은아래배벽동맥(Deep Inferior Epigastric Artery)의 천공지(Perforator)에 관한 해부학적 연구)

  • Kim, Jee Hoon;Lee, Paik Kwon;Rhie, Jong Won;Kim, Deog Im;Han, Seung Ho
    • Archives of Plastic Surgery
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    • v.35 no.1
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    • pp.28-35
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    • 2008
  • Purpose: The pedicle of transverse rectus abdominis myocutaneous(TRAM) flap and deep inferior epigastric arterial perforator flap is deep inferior epigastic artery (DIEA) and accurate anatomic knowledge about perforator of DIEA is very important for the elevation of these flap. The authors investigated a detailed vascular network of perforator of DIEA in Koreans. Methods: 24 fresh cadavers were studied. Among them, 15 were examined based on the plain X-ray examination for the distribution and location of perforator of DIEA. And 9 fresh cadavers were examined based on the 3-dimensional computed tomography(CT) study for the distance between ending point of perforator of DIEA and mother artery, the distance between most medial mother artery and midline, the distance between most lateral mother artery and midline, and the running type of perforators of DIEA. Results: Based on the plain X-ray examination, suitable(external diameter$${\geq_-}0.5mm$$) perforators of DIEA are located between the level of umbilicus and 8 cm below it. Based on the 3D-CT study, average distance between the ending point of perforator of DIEA and the mother artery is 30.26 mm on the left, 28.62 mm on the right, respectively. The average distance between most medial mother artery and midline is 17.13 mm on the left, 15.76 mm on the right, respectively. The average distance between most lateral mother artery and midline is 56.31 mm on the left, 50.90 mm on the right, respectively. The main running course of suitable perforators of DIEA is type a, which is a direct musculocutaneous perforator vessel from main vascular axis passing outward to join the subdermal plexus, directly. Conclusion: 3-dimensional computed tomography study as well as plain X-ray examination provided more accurate and detail informations about perforators of DIEA in Koreans. These informations will help us understand the detailed vascular anatomy and operation with ease and safe in the lower abdomen of Koreans.

A Study on Dose Distribution around Fletcher-Suit Colpostat Containing Cs-137 Source by a Computer (컴퓨터 의한 Fletcher-Suit Colpostat 주변의 Cs-137의 선량분포에 관한 연구)

  • Kang Wee-Saing
    • Radiation Oncology Journal
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    • v.7 no.2
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    • pp.305-311
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    • 1989
  • Fletcher-Suit colpostat has an internal structure to reduce dose to bladder and rectum. Some programs were developed to calculate dose at any point in water in three dimension around the colpostat containing Cs-137 tube, to find the shielding effect to dose by the internal structure, and to draw isodose curves and iso-shielding effect curves. Computer was an IBM compatible AT with EGA card and language was MS-Basic V6.0, Material, shape and geometry of the strucure, tube and colpostat were considered in algorithm for calculation of dose. Dose rates per unit mg. Ra. eq. in water calculated by a program were stored in auxiliary memory devices and retrieved in another programs. Isodose curves on medial side shrinked. Dose distribution was not symmetric about a transverse axis bisecting the colpostat. Reduction of dose was more excessive on top side than on bottom. Iso-shielding effect curve showed that the shielding effect was higher on top side than on bottom, and that there was shielding effect over almost all area of medial side. Such results were related to both shifted position of tube in the colpostat and asymmetric distribution of active source in the tube. Maximum of shielding effect was $49\%$ on top side and $44\%$ on bottom side. The direction of iso-shielding effect curve was generally radial from the center of active source. In treatment planning using Fletcher-Suit colpostat, the internal structure should be considered to find precise doses to bladder and rectum, etc.

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Evaluation of the Femoral Stem Implant in Canine Total Hip Arthroplasty: A Cadaver Study

  • Cho, Hyoung Sun;Kwon, Yonghwan;Kim, Young-Ung;Kang, Jin-Su;Lee, Kichang;Kim, Namsoo;Kim, Min Su
    • Journal of Veterinary Clinics
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    • v.36 no.1
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    • pp.53-61
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    • 2019
  • Total hip arthroplasty (THA) is a successful surgical treatment for both patients with chronical lameness and dogs who are nonresponsive to medical treatments, providing excellent joint function for returning dogs to the normal gait in 80% to 98% of hip dysplasia (HD) patients. The THA surgical implant system manufactured by BioMedtrix and Kyon are today widely accepted. When comparing the BioMedtrix biological fixation (BFX) system to the BioMedtrix cemented fixation (CFX) system, the many advantages of BFX, which include longer potential implant life, decreased risk of postoperative or later infection, and better implant stability, become evident. However, BFX implies a greater risk of femoral fracture during reaming and requires a more precise surgical technique to achieve good implant fit, given the press-fit nature of cementless THA. The purposes of this study are to both describe the mistakes and complications during stem implantation for beginner surgeons with both the BFX and the CFX systems and to document the initial result of 12 implantations in canine cadavers. Given the detailed evaluations of 3 specialists, who are Diplomate American College of Veterinary Surgeons (DACVS), only 3 of 11 stems were appropriately sized. Specifically, 6 stems were anteverted rather than being retroverted; further, although 7 stems were coaxial with the femoral long axis in the frontal plane, the other stems were in the varus at the frontal plane, with the proximal medial stem adjacent to the medial femoral cortex. Moderate angulation from the cranial to the caudal directions was found in 4 cases in the sagittal plane. Additionally, 1 case of femoral fissure and 1 case of perforated femoral cortex were reported. It is not easy for surgeons performing cementless THA for the first time to achieve a good result, even though they completed an educational course about it and given that catastrophic complications often occurred during early surgical clinical cases. Therefore, ex-vivo studies are sincerely required to get an expertise by rehearsing the preparation of the femoral envelop in isolated bones. Further studies should be conducted to achieve both highly accurate implant size and correct orientation during the preoperative planning. Additionally, surgeons' learning curve should be examined in future investigations.

KNEE: Basic Science and Injury of Bone (슬관절 주위 글격의 기초과학 및 스포츠 손상)

  • Kim Hee-Chun
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.2 no.2
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    • pp.77-81
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    • 2003
  • Purpose: The biomechanics and kinematics of knee joint were reviewed in this article. And then the common sports injuries were presented. Anatomy and Kinetics: None of the pairs of bearing surfaces in the knee joint is exactly congruent This allows the knee six degrees of freedom of motion. Tibiofemoral Kinematics: In flexion and extension, the axis of motion is not perpendicular to the medial-lateral plane of the joint, nor is it perpendicular to the axis of longitudinal rotation. This results in coupled varus angulation and internal rotation with flexion and in valgus angulation and external rotation with extension. Patellofemoral Articulation: Loads across the patellofemoral joint are indirectly related to the angle of knee flexion and directly related to the force generated within the quadriceps mechanism. Fractures of the Patella: Nonoperative treatment is indicated if the extensor mechanism is intact and if displacement of fragment is minimal. The specific type of internal fixation depends on the fracture pattern. It is important to repair retinaculum. Acute and Recurrent Patellar Instability: The degree of dysplasia and the extent of the instability play a large part in determining the success of nonoperative treatment. Patients who experience recurrent dislocations and patients with major anatomic variations require surgery to minimize their instability. Sports Injuries in School-age Atheletes: Patellar pain in young athletes groups a number of conditions, including Idiopathic Adolescent Anterior Knee Pain, Osgood- Schlatter Disease, and Sinding-Larsen-Johansson Disease.

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Introduction of Hindfoot Coronal Alignment View (후족부 관상면 배열 영상에 대한 고안)

  • Moon, Il-Bong;Jeon, Ju-Seob;Yoon, Kang-Cheol;Choi, Nam-Kil;Kim, Seung-Kook
    • Journal of radiological science and technology
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    • v.29 no.4
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    • pp.225-228
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    • 2006
  • Purpose: Accurate clinical evaluation of the alignment of the calcaneus relative to the tibia in the coronal plane is essential in the evaluation and treatment of hindfoot pathologic condition. Previously described standard anteroposterior, lateral, and oblique radiographic methods of the foot or ankle do not demonstrate alignment of the tibia relation to the calcaneus in the coronal plane. The purpose of this study was to introduce hindfoot coronal alignment view. Material : 1) Both feet were imaged simultaneously on an elevated, radiolucent foot stand equipment. 2) Both feet stood on a radiolucent platform with equal weight on both feet. 3) Both feet are located foot axis longitudinal perpendicular to the platform. 4) Silhouette tracing around both feet are made, and line is then drawn to bisect the silhouette of the second toe and the outline of the heel. 5) The x-ray beam is angled down approximately $15^{\circ} to $20^{\circ} Result : 1) This image described tibial axis and medial, lateral tuberosity of calcaneus. 2) Calcaneus do not rotated. 3) The view is showed by talotibial joint space. Conclusion: Although computed tomographic and magnetic resonance imaging techniques are capable of demonstrating coronal hindfoot alignment, they lack usefulness in most clinical situations because the foot is imaged in a non-weight bearing position. But hindfoot coronal alignment view is obtained for evaluating position changing of inversion, eversion of the hindfoot and varus, valgus deformity of calcaneus.

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c-Fos Expression in the Nucleus of the Solitary Tract in Response to Salt Stimulation in Rats

  • Kwak, Yong-Ho;Rhyu, Mee-Ra;Bai, Sun-Joon;Sa, Young-Hee;Kwon, Min-Jee;Lee, Bae-Hwan
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.6
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    • pp.437-443
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    • 2011
  • Salt signals in tongue are relayed to the nucleus of the solitary tract (NST). This signaling is very important to determine whether to swallow salt-related nutrition or not and suggests some implications in discrimination of salt concentration. Salt concentration-dependent electrical responses in the chorda tympani and the NST were well reported. But salt concentration-dependency and spatial distribution of c-Fos in the NST were not well established. In the present study, NaCl signaling in the NST was studied in urethane-anesthetized rats. The c-Fos immunoreactivity in the six different NST areas along the rostral-caudal axis and six subregions in each of bilateral NST were compared between applications of distilled water and different concentrations of NaCl to the tongue of experimental animals. From this study, salt stimulation with high concentration (1.0 M NaCl) induced significantly higher c-Fos expression in intermediate NST and dorsal-medial and dorsal-middle subregions of the NST compared to distilled water stimulation. The result represents the specific spatial distribution of salt taste perception in the NST.