• International Journal of Oral Biology
• /
• 제38권3호
• /
• pp.87-92
• /
• 2013

Periodontal inflammation increases the risk of tooth loss, particularly in cases where there is an associated loss of alveolar bone and periodontal ligament (PDL). Histological and morphometric evaluation of periodontal inflammation is difficult. Especially, the lengths of the periodontal ligament and interdental alveolar bone space have not been quantified. A quantitative imaging procedure applicable to an animal model would be an important clinical study. The purpose of this study was to quantify the loss of alveolar bone and periodontal ligament by evaluation with micro-computed tomography (micro-CT). Another purpose was to investigate differences in infections with systemic E. coli LPS and TNF-${\alpha}$ on E. coli lipopolysaccharide (LPS) in loss of alveolar bone and periodontal ligament model on mice. This study showed that linear measurements of alveolar bone loss were represented with an increasing trend of the periodontal ligament length and interdental alveolar process space. The effects of systemic E. coli LPS and TNF-${\alpha}$ on an E. coli LPS-induced periodontitis mice model were investigated in this research. Loss of periodontal ligament and alveolar bone were evaluated by micro-computed tomography (micro-CT) and calculated by the two- and three dimensional microstructure morphometric parameters. Also, there was a significantly increasing trend of the interdental alveolar process space in E. coli LPS and TNF-${\alpha}$ on E. coli LPS compared to PBS. And E. coli LPS and TNF-${\alpha}$ on E. coli LPS had a slightly increasing trend of the periodontal ligament length. The increasing trend of TNF-${\alpha}$ on the LPS-induced mice model in this experiment supports the previous studies on the contribution of periodontal diseases in the pathogenesis of systemic diseases. Also, our findings offer a unique model for the study of the role of LPS-induced TNF-${\alpha}$ in systemic and chronic local inflammatory processes and inflammatory diseases. In this study, we performed rapidly quantification of the periodontal inflammatory processes and periodontal bone loss using micro-computed tomography (micro-CT) in mice.

• 한국의학물리학회지:의학물리
• /
• 제32권4호
• /
• pp.165-171
• /
• 2021

Purpose: This study aimed to evaluate the effect of collimator width on effective atomic number (EAN), relative electron density (RED), and stopping power ratio (SPR) measured by dual-layer dual-energy computed tomography (DL-DECT). Methods: CIRS electron density calibration phantoms with two different arrangements of material plugs were scanned by DL-DECT with two different collimator widths. The first phantom included two dense bone plugs, while the second excluded dense bone plugs. The collimator widths selected were 64 mm×0.625 mm for wider collimators and 16 mm×0.625 mm for narrow collimators. The scanning parameters were 120 kVp, 0.33 second gantry rotation, 3 mm slice thickness, B reconstruction filter, and spectral level 4. An image analysis portal system provided by a computed tomography (CT) manufacturer was used to derive the EAN and RED of the phantoms from the combination of low energy and high energy CT images. The EAN and RED were compared between the images scanned using the two different collimation widths. Results: The CT images with the wider collimation width generated more severe artifacts, particularly with high-density material (i.e., dense bone). RED and EAN for tissues (excluding lung and bones) with the wider collimation width showed significant relative differences compared to the theoretical value (4.5% for RED and 20.6% for EAN), while those with the narrow collimation width were closer to the theoretical value of each material (2.2% for EAN and 2.3% for RED). Scanning with narrow collimation width increased the accuracy of SPR estimation even with high-density bone plugs in the phantom. Conclusions: The effect of CT collimation width on EAN, RED, and SPR measured by DL-DECT was evaluated. In order to improve the accuracy of the measured EAN, RED, and SPR by DL-DECT, CT scanning should be performed using narrow collimation widths.

• 한국방사선학회논문지
• /
• 제4권1호
• /
• pp.19-24
• /
• 2010

콘빔형 소동물용 CT 장치는 바이오-의료분야의 기초 실험에 활발히 응용되고 있다. $10{\mu}m$의 직경을 가진 텅스텐 와이어(wire)와 물 팬텀을 이용하여 비교적 간단한 방법으로 소동물용 CT 장치를 평가할 수 있는 방법을 제시하였다. X선 튜브가 안정적으로 장시간 운전 가능한 조건에서 $1^{\circ}$ 간격으로 360개의 투영영상을 획득하고, 영상재구성을 통하여 슬라이스 영상 및 3차원 영상을 얻었다. 콘빔형 소동물용 CT 장치는 배율 1.07배 위치에서 13.78lp/mm(공간해상도 $36.2{\mu}m$)를 나타내었고, 80kV의 관전압에서 CNR 10.33 및 S/N 5.87을 보였다.

• 한국임상수의학회지
• /
• 제30권5호
• /
• pp.390-393
• /
• 2013

폐염전으로 진단한 소형견 4 마리의 흉부 방사선 사진 및 컴퓨터단층촬영 (CT) 영상을 평가하였다. 흉수 및 폐염전이 발생한 폐엽의 밀도 증가는 4 마리 환자의 흉부 방사선 사진 및 CT 영상에서 모두 확인되었다. 폐염전이 발생한 기시부에서의 기관지의 협착/허탈은 CT 영상을 통해 4 마리의 개에서 모두 확인된 반면, 흉부 방사선 사진에서는 오직 1 마리의 환자에서만 확인되었다. 폐포성 폐기종 패턴 (vesicular emphysema pattern) 역시, CT 영상을 통해 4 마리의 환자에서 모두 확인된 반면, 흉부 방사선 사진에서는 3 마리에서 관찰되었다. 폐염전의 특이소견은 폐포성 폐기종 패턴과 폐염전이 발생한 폐엽 기시부의 기관지의 협착/허탈이며, 이 소견은 흉부 방사선 사진보다 CT 영상을 통해 좀 더 용이하고 빈번하게 확인되었다.

• The Korean Journal of Pain
• /
• 제23권2호
• /
• pp.137-141
• /
• 2010

Background: Facet joint have been implicated as a source of chronic low back pain. Radiofrequency denervation has demonstrated the most solid evidence. To increase safety and efficacy of treatment, computed tomography (CT) guidance injection has been used in several disease. The purpose of this study was to evaluate the efficacy of CT-guided radiofrequency rhizotomy in the treatment of facet joint pain. Methods: A total of 40 patients were randomized to undergo radiofrequency facet joint denervation under CT guidance or C-arm guidance. All patients were examined visual analogue scale (VAS) score before treatment, 1 month, and 3 months after treatment. Results: The VAS in both groups showed significant improvement over the 1-month interval. No significant difference in the VAS score among the group was observed. Conclusions: In this study there was no significant difference between CT guidance lumbar rhizotomy and C-arm guidance lumbar rhizotomy. Therefore CT-guided radiofrequency denervation of the lumbar facet joint was a minimally invasive technique that appears effective.

• 한국방사선학회논문지
• /
• 제10권1호
• /
• pp.45-51
• /
• 2016

본 연구에서는 비등방성 2차원 확산 기반 필터를 이용하여 전산화단층영상(computed tomography, CT)의 노이즈 제거와 공간분해능을 향상하고자 하였다. 실험은 4-채널 다중검출기 전산화단층영상기기(4-channel multi-detector computed tomography, MDCT)를 이용하였으며, CT 영상품질 평가를 위해 미국 의학물리학자협의회(american association of physicists in medicine, AAPM) CT 성능 평가용 팬톰을 사용하였다. X-선 조사 조건은 120 kVp, 100 mAs로 고정한 후 ultra-high resolution으로 10 mm 축 방향 스캔 하였다. 본 연구에서 제안한 비등방성 2차원 확산 기반 필터는 원 영상에 각 픽셀에 가중치 1.2를 곱하고 0.4% 히스토그램 스트레칭을 통해 영상의 대조도를 증가시킨 후 비등방성 2차원 확산 필터를 적용하였다. 그 결과, 공간분해능은 원 영상에서 0.75 mm까지 구분되었지만 제안한 비등방성 2차원 확산 기반 필터 영상에서는 0.40 mm까지 구분되었다. 원 영상의 노이즈는 46.0, 제안한 비등방성 2차원 확산 기반 필터 영상의 노이즈는 33.5로 27.2%가 감소하였다. 우리가 제안한 비등방성 2차원 확산 기반 필터는 CT의 노이즈 제거와 공간분해능을 향상시킬 수 있었다.

• Tuberculosis and Respiratory Diseases
• /
• 제80권4호
• /
• pp.368-376
• /
• 2017

Background: A ground-glass nodule (GGN) represents early-stage lung adenocarcinoma. However, there is still no consensus for preoperative staging of GGNs. Therefore, we evaluated the need for the routine use of positron emission tomography/computed tomography (PET)/computed tomography (CT) scans and brain magnetic resonance imaging (MRI) during staging. Methods: A retrospective analysis was undertaken in 72 patients with 74 GGNs of less than 3 cm in diameter, which were confirmed via surgery as malignancy, at the Samsung Medical Center between May 2010 and December 2011. Results: The median age of the patients was 59 years. The median GGN diameter was 18 mm. Pure and part-solid GGNs were identified in 35 (47.3%) and 39 (52.7%) cases, respectively. No mediastinal or distant metastasis was observed in these patients. In preoperative staging, all of the 74 GGNs were categorized as stage IA via chest CT scans. Additional PET/CT scans and brain MRIs classified 71 GGNs as stage IA, one as stage IIIA, and two as stage IV. However, surgery and additional diagnostic work-ups for abnormal findings from PET/CT scans classified 70 GGNs as stage IA, three as stage IB, and one as stage IIA. The chest CT scans did not differ from the combined modality of PET/CT scans and brain MRIs for the determination of the overall stage (94.6% vs. 90.5%; kappa value, 0.712). Conclusion: PET/CT scans in combination with brain MRIs have no additional benefit for the staging of patients with GGN lung adenocarcinoma before surgery.

• Nuclear Medicine and Molecular Imaging
• /
• 제40권5호
• /
• pp.271-274
• /
• 2006

We report the case of a 64-year-old man with superior vena cava (SVC) syndrome due to tumor thrombus from recurrent hepatocellular carcinoma (HCC). He presented with new onset of facial swelling for 10 days. HCC was detected ten years ago. He has undergone repeated transcatheter arterial embolization (TAE) and chemotherapy. Chest computed tomography (CT) demonstrated tumor thrombus in the SVC extending to right atrium. He underwent whole body F-18 fluorodeoxyglucose(FDG) positron emission tomography/computed tomography (PET/CT) scanning for assessing the effect of TAE in HCC. F-18 FDG PET/CT showed increased uptake in the residual liver mass indicating viable tumor. There was another intense F-18 FDG accumulation in SUV extending to right atrium to suggest tumor thrombus. This case illustrates that F-18 FDG PET/CT is useful to identification of distant metastases as well as assessment of response to therapy in long-term survival HCC patients.

• Nuclear Medicine and Molecular Imaging
• /
• 제41권4호
• /
• pp.335-336
• /
• 2007

Meniscus-like presentation of ulcerating gastric carcinoma on upper gastrointestinal series radiograph was first described in 1921 by Carman and has since been known as a useful differential diagnostic sign in radiology. In 1982 using then newly introduced computed tomography (CT) Widder and Mueller revisited the meniscus sign. Their study was primarily focused on a dynamic assessment of the demonstrability of the meniscus sign that largely depends on the judgment and technical skill of examiner, especially graded compression and patient positioning. One year earlier Balfe et al. assessed the diagnostic reliability of gastric wall thickening as observed on CT scan in adenocarcinoma, lymphoma and leiomyosarcoma and concluded that it is not a reliable finding. In contrast, however, Lee et al. recently emphasized that the wall thickness measurement on CT of exophytic carcinoma, myoma and ulcers was a useful diagnostic means. Thus, it appears that gastric wall thickening or mucosal heave-up is by itself not as reliable as the meniscus sign. The electronic search of world literature failed to disclose earlier report of this sign demonstrated by $^{18}F-FDG$ positron emission tomography and computed tomography (PET/CT). The present communication documents $^{18}F-FDG$ PET/CT finding of the meniscus sign as encountered in a case of ulcerating gastric carcinoma, the histological diagnosis of which was moderately differentiated tubular adenocarcinoma. Unlike most gastric tumors without ulceration that tend to unimpressively accumulate $^{18}F-FDG$ the present case of Borrmann type III gastric carcinoma demonstrated markedly increased $^{18}F-FDG$ uptake.

• Imaging Science in Dentistry
• /
• 제32권2호
• /
• pp.119-122
• /
• 2002

Two cases of Eagle's syndrome are reported. The first case involved a 31-year-old man who complained of pain in his throat and pain at preauricular area on turning his head. Panoramic and computed tomography (CT) views showed bilateral stylohyoid ligament ossification. The symptoms were relieved after surgical removal. The second case involved a 56-year-old female whose chief complaints were a continuous dull pain and occasional 'shooting' pain on lower left molar area. During the physical examination, an ossified stylohyoid ligament was palpated at the left submandibular area. Panoramic and CT images showed prominent bilateral stylohyoid ligament ossification. CT scans also showed hypertrophy of left medial and lateral pterygoid muscles. The symptoms were relieved after medication. CT is a useful tool for the examination of ossified stylohyoid ligaments and studying the relationship between Eagle's syndrome and adjacent soft tissue.