• Title/Summary/Keyword: 컴퓨터 단층촬영술

Search Result 18, Processing Time 0.029 seconds

Theory of X-ray microcomputed tomography in dental research: application for the caries research (치과 분야 연구에서 미세전산화 단층촬영술의 이론: 치아우식증에 대한 적용)

  • Park, Young-Seok;Bae, Kwang-Hak;Chang, Ju-Hea;Shon, Won-Jun
    • Restorative Dentistry and Endodontics
    • /
    • v.36 no.2
    • /
    • pp.98-107
    • /
    • 2011
  • Caries remains prevalent throughout modern society and is the main disease in the field of dentistry. Although studies of this disease have used diverse methodology, recently, X-ray microtomography has gained popularity as a non-destructive, 3-dimensional (3D) analytical technique, and has several advantages over the conventional methods. According to X-ray source, it is classified as monochromatic or polychromatic with the latter being more widely used due to the high cost of the monochromatic source despite some advantages. The determination of mineral density profiles based on changes in X-ray attenuation is the principle of this method and calibration and image processing procedures are needed for the better image and reproducible measurements. Using this tool, 3D reconstruction is also possible and it enables to visualize the internal structures of dental caries. With the advances in the computer technology, more diverse applications are being studied, such automated caries assessment algorithms.

Balthazar Computed Tomographic Severity Index Application for Experimental Acute Necrotizing Pancreatitis in Dogs (개의 실험적 급성 괴사성 췌장염 평가에서 Balthazar Computed Tomographic Severity Index의 적용)

  • Choi, Ji-Hye;Choi, Min-Cheol;Yoon, Jung-Hee
    • Journal of Veterinary Clinics
    • /
    • v.27 no.6
    • /
    • pp.686-692
    • /
    • 2010
  • Computed tomography (CT) is considered as gold standard in evaluating pancreatitis in human, but there have been only a few studies in veterinary field. Balthazar CT severity index (CTSI) used to assess the severity of acute necrotizing pancreatitis in human could be applicable to dogs, because the severity of acute pancreatitis depends on the area of pancreatic necrosis in dogs more than in human. In this study, 25 adult, clinically healthy beagle dogs were used. CT examinations was performed in normal pancreas, positive control group and acute necrotizing pancreatitis induced by autologous bile injection. Balthazar CTSI was applied to canine acute necrotizing pancreatitis in contrastenhanced CT image and compared with the result of histopathologic examination. The Hounsfield unit (HU) of normal canine pancreas was $52.44{\pm}4.58$ and the density was significantly decreased in acute necrotizing pancreatitis (P < .05). In contrast-enhanced CT examination, pancreatic density was decreased significantly and this area was compatible to pancreatic necrosis. Balthazar CTSI showed positive correlation with histopathologic evaluation with a sensitivity of 100% and a specificity of 88.89%. Balthazar CTSI can be applied to evaluate the severity of acute necrotizing pancreatitis in dogs.

Availability of Positron Emission Tomography-Computed Tomography for the Diagnosis of the Soft Tissue Tumor through Ultrasound-Guided Biopsy (초음파 유도하 침 생검을 이용한 연부조직 종양의 진단에 있어 양전자방출 컴퓨터 단층촬영술의 유용성)

  • Jun, Se Bin;Kim, Jeung Il;Lee, In Sook;Song, You Seon;Choi, Kyung Un
    • Journal of the Korean Orthopaedic Association
    • /
    • v.56 no.5
    • /
    • pp.398-403
    • /
    • 2021
  • Purpose: A biopsy is needed to diagnose soft tissue tumors. However, it is extremely difficult to pinpoint the site of a tumor due to the heterogeneity of sarcomas. Thus, even when an open biopsy is conducted, it is difficult to diagnose a soft tissue tumor. In such cases, an ultrasound (US)-guided biopsy is used to improve the diagnostic accuracy. This study evaluated the accuracy of US-guided biopsy for a diagnosis of soft tissue tumors found initially in a magnetic resonance (MR) perfusion and assessed the availability of positron emission tomography-computed tomography (PET-CT) for a diagnosis of soft tissue tumors. Materials and Methods: From January 2014 to December 2018, the US-guided biopsy was performed on 152 patients with a suspected soft tissue tumor found in an MR perfusion and 86 cases were definitively diagnosed with a soft tissue tumor. The accuracy of the US-guided biopsy was assessed retrospectively. Among the 86 cases, only MR perfusion was used before the biopsy in 50 cases, while both MR perfusion and PET-CT was conducted on 36 cases. The accuracy was analyzed to determine if the PET-CT could improve the precision of a biopsy. Results: From 86 cases, 34 out of 50 cases, in which only MR perfusion had been conducted, matched the result of the definitive diagnosis and the US-guided biopsy. 32 out of 36 cases, in which both PET-CT and MR perfusion were conducted, matched the definitive diagnosis and the US-guided biopsy. These results show significant differences in the accuracy of US-guided biopsy. In the case of soft tissue sarcomas, 6 out of 12 cases, in which only MR perfusion had been conducted, matched the result of the definitive diagnosis and the US-guided biopsy. 17 out of 18 cases, in which both PET-CT and MR perfusion were conducted, matched the definitive diagnosis. Moreover US-guided biopsy also showed significant differences in the accuracy of US-guided biopsy. Conclusion: In diagnosing soft tissue tumors, a US-guided biopsy is a well-known tool for its high accuracy. However, the heterogeneity of sarcoma makes it difficult to locate the exact site for a biopsy using only MR perfusion. Thus, the use of PET-CT will meaningfully improve the accuracy of a diagnosis by precisely targeting the site for the US-guided biopsy.

Heart-base Tumors in Three Yorkshire Terriers (세 마리 개에서 발생한 심저부 종양 증례)

  • Kwon, Jeong-Kuk;Chung, Woo-Jo;Jang, Ju-Won;Kim, Young-Il;Chung, Dae-Won;Jeoung, Seok-Young;Chung, Jin-Young
    • Journal of Veterinary Clinics
    • /
    • v.31 no.4
    • /
    • pp.303-306
    • /
    • 2014
  • Three Yorkshire Terriers (12-year-old, 13-year-old, and 15-year-old castrated males) with respiratory distress, coughing and anorexia were the subjects of this report. In laboratory examinations, there were no remarkable findings. However, the thoracic radiographic findings included a large mass of soft tissue density in the cardiac base region, tracheal elevation, and aortic bulging in all three Yorkshire Terriers. There were no remarkable findings in the abdominal radiographs. In echocardiography, a homogeneous hyperechoic mass around the aorta and bicuspid valve regurgitation were found in all three dogs. There were no remarkable findings in abdominal ultrasonography. Computed tomographic findings showed a large well -defined heterogeneous mass in the cranial vena cava, which was dominant in the left side in all three Yorkshire Terriers. The mass sizes were about $3{\times}4cm$. In post-contrast scanning, contrast enhancement was evident. These cases were diagnosed as heart-base tumor. Treatments provided to the three dogs were based on symptomatic medical management of cardiac failure and tracheal collapse. Case 1 (12-year-old) survived for 3 months, case 2 (13-year-old) for 5 months, and case 3 (15-year-old) for 32 months after the diagnosis. Our results show that the clinical findings, thoracic radiography, echocardiography, computed tomography (CT) and symptomatic medical management in dogs suspected to have heart base tumor.

Nasopharyngeal Polyp in a Domestic Short Hair Cat (단모종 집고양이의 코인두 폴립 증례)

  • Lee, Da-Mi;Yu, Do-Hyeon;Nho, Dong-Ho;Song, Ru-Hui;Kim, Jun-Hwan;Cho, Ho-Seong;Park, Jin-Ho;Park, Chul
    • Journal of Veterinary Clinics
    • /
    • v.28 no.4
    • /
    • pp.435-437
    • /
    • 2011
  • A 2-year-old, domestic short hair cat presented because of a 2-year history of chronic nasal discharge and chronic otitis. Examination of the oral cavity revealed a mass in the nasopharynx. For further examination, computed tomography (CT) was performed and large polyp was revealed on the nasopharyngeal area. Traction removal of the polyp was performed using a spay hook. After removal of the mass, Horner's syndrome was developed but resolved spontaneously within 14 days.

Clinical Study of Pulmonary Thromboembolism (폐혈전색전증의 임상적 연구)

  • Bak, Sang-Myeon;Lee, Sang-Hwa;Lee, Sin-Hyung;Sin, Cheol;Cho, Jae-Youn;Shim, Jae-Jeong;In, Kwang-Ho;Kang, Kyung-Ho;Yoo, Se-Hwa
    • Tuberculosis and Respiratory Diseases
    • /
    • v.50 no.1
    • /
    • pp.106-116
    • /
    • 2001
  • Background : Pulmonary thromboembolism is relatively frequent and potentially fatal. However, it is commonly misdiagnosed. The incidence of pulmonary thromboembolism is not decreasing despite advances in diagnosis and effective prophylatic measures. Its potential for significant sequela necessitates a prompt diagnosis and treatment. Unfortunately, there are many difficulties and problems regarding accurate diagnosis. There is a low prevalence of deep vein thrombosis and pulmonary thromboembolism in Korea and only few reports on this subject are available. Method : The clinical features of 36 patients, who were diagnosed with pulmonary thromboembolism at the Korea University medical center, were reviewed. Results : 1) There was no significant difference in prevalence between men an women, and the mean age was 50.9 years in men 59.2 years in women. 2) The frequent causes of pulmonary thromboembolism were malignancies (22.2%), surgery (22.2%), and heart disease(8.2%). Specific causes were not identified in 33.3%. 3) The most common symptom was dyspnea(72.2%), and the most common sign was tachypnea(61.1%). 4) The EKG findings were normal in 28.6%, an S1Q3T3 pulmonale pattern in 25.7%, ST or QRS changes in others. 5) The chest X-ray findings indicated pulmonary infiltration in 37.5%, cardiomegaly in 15.6%, pleural effusion in 12.5%, and normal in 27.8%. The perfusion lung scan showed a high probability in 66.7%, and intermediate or low probability in 33.3%. 6) The pulmonary arterial pressure(PAP) in the high probability groups was 57.9mmHg with a higher mortality rate(35%). Conclusion : Pulmonary thromboembolism is not uncommon in Korea and its clinical features do not differ greatly from thase reported in the literature. When pulmonary thromboemblism of unknown causes are diagnosed, a search for an occult malignancy is recommended. Rapid diagnosis and treatment are achieved when thromboemblism is suspected.

  • PDF

Analysis of Anatomical Conformity of Straight Antegrade Humeral Intramedullary Nail in Korean (한국인에서의 직선형 전향적 상완골 골수 내 금속정의 해부학적 적합성 분석)

  • Choi, Sung;Jee, Seungmin;Hwang, Seongmun;Shin, Dongju
    • Journal of the Korean Orthopaedic Association
    • /
    • v.56 no.6
    • /
    • pp.498-503
    • /
    • 2021
  • Purpose: The aim of this study were to find ideal entry point of straight antegrade humeral intramedullary nail (SAHN) for the treatment of proximal humerus fracture in Korean and to analyze anatomical conformity using computed tomography. Materials and Methods: From May 2014 to October 2016, the study was conducted retrospectively on 74 Korean patients who had taken computed tomography on both normal and affected shoulder joint as result of shoulder injury. The mean age of the patients was 64.5 years (range, 22-95 years). Radiologic evaluation was done using multiplanar reconstruction technique of the computer tomography on normal proximal humerus. We located ideal entry point of SAHN as the point where humerus intramedullary center axis and humeral head meet. Distance between the entry point and local anatomical landmark was measured. We defined the critical distance as the distance between entry point and the most medial point of the supraspinatus attachment site. For adequate fixation and avoidance of injury to rotator cuff, critical distance should be over 8 mm according to Euler, and we defined the critical type when it is less than 8 mm. Critical distance, sex, age, height, body weight, body mass index was evaluated for the statistical significance. Results: The ideal entry point was as follows: the mean anteroposterior distance, the sagittal distance to the lateral margin of bicipital groove, was 11.5 mm and the mean mediolateral distance, the coronal distance to the lateral margin of grater tuberosity, was 20.5 mm. The mean critical distance, distance from the entry point to the just medial to insertion of the supraspinatus tendon, was 8.0 mm. Critical type with critical distance less than 8 mm was found in 41 in 74 patients (55.4%). Conclusion: The ideal entry point of SAHN in Korean was located on 11.5 mm posteriorly from the lateral margin of bicipital groove and 20.5 mm medially from lateral margin of greater tuberosity. More than half of the cases were critical type. Since critical type can possibly cause rotate cuff injury during nail insertion on entry point, surgeon should consider anatomical variance before choosing surgical option.

Diagnostic Approach to a Soft Tissue Mass (연부조직 종양의 진단적 접근)

  • Chun, Young Soo;Song, Seung Hyun
    • Journal of the Korean Orthopaedic Association
    • /
    • v.54 no.4
    • /
    • pp.293-301
    • /
    • 2019
  • Soft tissue masses of the extremities and torso are a common problem encountered by orthopaedic surgeons. Although these soft tissue masses are often benign, orthopaedic surgeons need to recognize the key features differentiating benign and malignant masses. An understanding of the epidemiology and clinical presentation of soft tissue masses is needed to develop a practical approach for evaluation and surgical management. Size and depth are the two most important factors on which triage decisions should be based. In a differential diagnosis of a tumor, it is important to know the characteristics of the soft tissue mass through detailed history taking and physical examinations before the diagnostic procedures. A variety of imaging studies, such as simple radiography, ultrasound, magnetic resonance imaging, positron emission tomography, computed tomography, bone scan, and angiography can be used to diagnose tumors. Know the ledge of advantages and disadvantages of each imaging study is essential for confirming the characteristics of the tumor that can be observed in the image. In particular, ultrasonography is convenient because it can be performed easily in an outpatient clinic and its cost is lower than other image studies. On the other hand, the accuracy of the test is affected by the skill of the examiner. A biopsy should be performed to confirm the tumor and be performed after all imaging studies have been done but before the final treatment of soft tissue tumors. When a biopsy is to be performed, careful attention to detail with respect to multidisciplinary coordination beforehand, cautious execution of the procedure to minimize complications, and expedient follow-up and referral to a musculoskeletal oncologist when appropriate, are essential.

Convergence and integration study related to development of digital contents for radiography training using dental radiograph and augmented reality (치과방사선사진과 증강현실을 활용한 방사선촬영법 숙련용 디지털 콘텐츠 개발에 대한 융복합 연구)

  • Gu, Ja-Young;Lee, Jae-Gi
    • Journal of Digital Convergence
    • /
    • v.16 no.12
    • /
    • pp.441-447
    • /
    • 2018
  • This study aims to develop digital techniques that enable repeated practice of dental radiography using augmented reality technology. A three-dimensional object was fabricated by superimposing a photograph of an adult model and a computed tomography image of a manikin phantom. The system was structured using 106 radiographs such that one of these saved radiographs is opened when the user attempts to take a radiograph on a mobile device. This system enabled users to repeatedly practice at the pre-clinical stage without exposure to radiation. We attempt to contribute to enhancing dental hygienists' competency in dental radiography using these techniques. However, a system that enables the user to actually take a radiograph based on face recognition would be more useful in terms of practice, so additional studies are needed on the topic.