• Journal of Yeungnam Medical Science
• /
• 제38권2호
• /
• pp.95-106
• /
• 2021

Infections involving the heart are becoming increasingly common, and a timely diagnosis of utmost importance, despite its challenges. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a recently introduced diagnostic tool in cardiology. This review focuses on the current evidence for the use of FDG PET/CT in the diagnosis of infective endocarditis, cardiac implantable device infection, left ventricular assist device infection, and secondary complications. The author discusses considerations when using FDG PET/CT in routine clinical practice, patient preparation for reducing physiologic myocardial uptake, acquisition of images, and interpretation of PET/CT findings. This review also functions to highlight the need for a standardized acquisition protocol.

• 한국임상수의학회지
• /
• 제20권4호
• /
• pp.519-522
• /
• 2003

An appearance of herniated intervertebral disc into thoracolumbar vertebral canal was evaluated in two patients using computed tomography (CT). Before CT scanning, plain radiography and myelography were performed in both cases. CT images were compared to those of myelography. Dogs were positioned in sternal recumbency under inhalation anesthesia and transverse slices with 2 mm thickness were obtained around thoracolumbar region. The transverse CT images were examined using both vertebral and spiral window mode. The most common findings on CT images were loss of vertebral canal epidural fat, bulging of vertebral canal disc margins, displacement of spinal cord and flatted vertebral canal. Whereas, narrowed intervertebral disc space and simple extradural pattern were the main findings on plain and contrast radiographs. CT imges showed the extent of the herniated disc lesion, type II intervertebral disc hernation, and the displacement of spinal cord in detail in both occations. It is considered that degree and precise localization of the intervertebral disc herniation and subtle lesion of spinal cord could be identified accurately using computed tomography.

• Imaging Science in Dentistry
• /
• 제50권4호
• /
• pp.291-298
• /
• 2020

Purpose: The detection and exact localization of penetrating foreign bodies are crucial for the appropriate management of patients with dentoalveolar trauma. This study compared the efficacy of cone-beam computed tomography (CBCT) and spiral computed tomography (CT) scans for the detection of different foreign bodies composed of 5 frequently encountered materials in 2 sizes. The effect of the location of the foreign bodies on their visibility was also analyzed. Materials and Methods: In this in vitro study, metal, tooth, stone, glass, and plastic particles measuring 1×1×1 mm and 2×2×2 mm were prepared. They were implanted in a sheep's head in the tongue muscle, nasal cavity, and at the interface of the mandibular cortex and soft tissue. CBCT and spiral CT scans were taken and the visibility of foreign bodies was scored by 4 skilled maxillofacial radiologists who were blinded to the location and number of foreign bodies. Results: CT and CBCT were equally accurate in visualizing metal, stone, and tooth particles of both sizes. However, CBCT was better for detecting glass particles in the periosteum. Although both imaging modalities visualized plastic particles poorly, CT was slightly better for detecting plastic particles, especially the smaller ones. Conclusion: Considering the lower patient radiation dose and cost, CBCT can be used with almost equal accuracy as CT for detecting foreign bodies of different compositions and sizes in multiple maxillofacial regions. However, CT performed better for detecting plastic particles.

• Imaging Science in Dentistry
• /
• 제44권3호
• /
• pp.177-183
• /
• 2014

Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of periradicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

• 전기전자학회논문지
• /
• 제23권3호
• /
• pp.768-776
• /
• 2019

4차 산업 혁명 시대를 맞이하여, 최근 기계, 전자 부품의 설계, 제조, 검사에 첨단 IT 기술을 융합하는 사례가 늘고 있다. 본 연구에서는 최근에 구축된 산업용 X-ray CT(computed tomography)를 사용한 산업용 부품의 검사에 대한 최신기술에 대해서 다룬다. 먼저 구축된 첨단의 최신 산업용 CT의 구조와 원리에 대해서 설명하며, 이러한 장비의 역할과 성능에 대해서 설명하고, 본 장비의 분석기법을 보완하기 위한 새로운 연구기반의 구축에 대해서 다룬다. 특히 장비의 출력데이터를 Matlab과 같은 범용 연구 툴로 전송하여 연구를 진행할 수 있는 기반을 구축하며, 이를 토대로 기존의 운용 소프트웨어가 제공하지 못했던 보조적인 3D user interface와 3차원 영상처리를 위한 플랫폼을 구축하는 연구를 진행 하였다. 산업용 3차원 X-ray는 아직 소개 된지 얼마 되지 않은 첨단의 고가의 장비로서 이를 활용할 연구의 종류와 내용이 매우 풍부한 주제로, 이러한 기초적인 연구기반은 추후의 보다 발전적인 연구를 위한 아주 유용한 토대가 될 것으로 판단된다.

• 한국방사선학회논문지
• /
• 제11권6호
• /
• pp.453-458
• /
• 2017

컴퓨터단층촬영 (CT:Computed Tomography)은 환자의 정확한 진단을 위해 진단참고준위인 전산화 단층촬영 선량지표 (CTDI: Computed Tomography Dose Index)와 (DLP:Dose Length Product)의 정보를 제공한다. 그러나 CT 장비가 제공하는 진단참고준위는 테이블 높이에 따른 선량의 변화를 제공하지 않는다. 이번 연구는 컴퓨터단층촬영 검사 시 최적화된 이미지와 최소선량을 찾기 위하여 컴퓨터단층촬영 테이블 높이 변화에 따른 이미지와 선량을 팬텀(PMMA: Polymethyl Methacrylate)을 사용하여 비교 평가하였다. 성인의 복부와 같은 두께인 32 cm PMMA 팬텀을 촬영할 경우 테이블 높이에 따른 선량 변화는 거의 없었다. 그러나 이미지의 노이즈(Noise) 평가에서는 테이블 높이에 따라 노이즈 변동 폭이 크게 발생되었다. 그리고 16 cm PMMA 팬텀인 경우는 노이즈의 변화는 작지만 선량변화는 약 30 % 발생하였다. 결론적으로 컴퓨터단층촬영 (CT:Computed Tomography)의 검사 시에는 환자의 두께에 중심에 정확하게 일치시켜야 한다. 또한 최적화된 이미지와 최소선량으로 검사하기 위해서는 테이블 높이 설정이 중요할 것으로 사료된다.

• Imaging Science in Dentistry
• /
• 제36권2호
• /
• pp.111-116
• /
• 2006

PET/CT is a new imaging technology that combines high-quality Positron Emission Tomography (PET) and Computed Tomography (CT). This imaging provides simultaneous anatomical and metabolic information. Therefore PET/CT is useful diagnostic modality for early detection of malignant tumor, accurate staging, decision on therapeutic plan, monitoring response to therapy and rapid detection of recurrence. We report oral and maxillofacial cancers diagnosed by using PET/CT and the usefulness of PET/CT in the evaluation of postoperative recurrence.

• Journal of Radiation Protection and Research
• /
• 제49권3호
• /
• pp.141-150
• /
• 2024

Background: Computed tomography (CT) scans in the Republic of Korea have spiked, reaching approximately 9 million examinations annually in 2017. CT provides significant medical benefits, but radiation exposure remains a concern. This study aims to analyze CT scans in Korea, as a basis study for radiation safety management. Materials and Methods: The raw data of total CT scans was obtained from the Health Insurance Review & Assessment Service and analyzed by CT scan type, patients' age and sex, and medical facility type. CT scans trends were analyzed considering the disease incidence. Results and Discussion: In 2017, CT scans accounted for 8,977,300. Usage per capita was 0.18 in males and 0.17 in females. CT scans increased with age until the 50- to 59-year-old groups, then decreased. CT scans were high in abdominal/pelvic (35%), chest (26%), and head (22%) regions due to higher disease rates. Head CT was most frequently used for infants and children. Abdominal/pelvic, chest, and spine CT were more frequent for older groups. The CT scans in the upper and lower extremities was high in child and juvenile groups. Chest and abdominal/pelvic CTs were higher in males, whereas spine, whole spine, and CT densitometry were higher in females. The proportion of CT scans of tertiary and general hospitals, hospitals, and clinics accounted for ≥80%, 13%, and 5%, respectively. Abdomen/pelvis, chest, and head/neck CTs were mostly conducted in tertiary and general hospitals, spine CT in hospitals and clinics, extremity CT in hospitals, and CT densitometry in clinics. Conclusion: The trend of CT scans varied based on the incidence rate for each patient's sex and age, and serious illness diagnosis by medical facility type. The results of this study provide data and guidance for evaluating the radiation exposure of the Korean population by CT and developing management policies for medical radiation safety.

• 대한소아치과학회지
• /
• 제25권3호
• /
• pp.493-498
• /
• 1998

1. CT에 의한 매복치의 위치결정은 적절한 치료계획의 수립을 가능하게 하여 시술시간의 단축과 인접치, 인접구조물의 손상을 줄여 시술후의 부작용을 줄일 수 있었다. 2. 매복된 영구치의 견인시 CR를 활용한 결과 개창부위의 정확한 위치결정과 예후에 대한 예측이 가능하였다. 3. 평면방사선사진의 판독후 악골내 병소가 의심되어 CT를 활용한 결과 병소의 확진이 가능하였다. 4. 소아의 CT촬영은 평면 방사선 촬영에 비해 증가된 방사선 피폭량, 높은 수가 때문에 적절한 증례의 선택이 중요하다.

• 한국방사선학회논문지
• /
• 제9권2호
• /
• pp.109-115
• /
• 2015

전산화단층촬영장치(computed tomography, CT)을 이용한 검사의 경우 방사선량의 분포가 일반 X선 장치와 차이가 있고 검사로 인한 방사선 피폭이 많은 것으로 알려져 있다. 그러나 검사 결과의 정확성에 대한 신뢰도가 높아 그 이용도는 계속적으로 증가하고 있다. 이와 같은 상황을 고려하여 기존에 발표된 자료를 바탕으로 CT장치, CT검사에서 방사선량, 진단참고준위 그리고 검사 시 방사선량 감소 방안에 대해 알아보았다.