• 제목/요약/키워드: Defect Imaging

검색결과 267건 처리시간 0.026초

Customized Cranioplasty Implants Using Three-Dimensional Printers and Polymethyl-Methacrylate Casting

  • Kim, Bum-Joon;Hong, Ki-Sun;Park, Kyung-Jae;Park, Dong-Hyuk;Chung, Yong-Gu;Kang, Shin-Hyuk
    • Journal of Korean Neurosurgical Society
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    • 제52권6호
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    • pp.541-546
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    • 2012
  • Objective : The prefabrication of customized cranioplastic implants has been introduced to overcome the difficulties of intra-operative implant molding. The authors present a new technique, which consists of the prefabrication of implant molds using three-dimensional (3D) printers and polymethyl-methacrylate (PMMA) casting. Methods : A total of 16 patients with large skull defects (>100 $cm^2$) underwent cranioplasty between November 2009 and April 2011. For unilateral cranial defects, 3D images of the skull were obtained from preoperative axial 1-mm spiral computed tomography (CT) scans. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of the cranium as a model. For bilateral cranial defects, precraniectomy routine spiral CT scan data were merged with postcraniectomy 3D CT images following a smoothing process. Prefabrication of the mold was performed by the 3D printer. Intraoperatively, the PMMA implant was created with the prefabricated mold, and fit into the cranial defect. Results : The median operation time was $184.36{\pm}26.07$ minutes. Postoperative CT scans showed excellent restoration of the symmetrical contours and curvature of the cranium in all cases. The median follow-up period was 23 months (range, 14-28 months). Postoperative infection was developed in one case (6.2%) who had an open wound defect previously. Conclusion : Customized cranioplasty PMMA implants using 3D printer may be a useful technique for the reconstruction of various cranial defects.

Risk factors of ocular involvement in children with mitochondrial respiratory chain complex defect

  • Chae, Jung-Hyun;Lee, Jung-Hun;Kim, Kyo-Ryung;Byeon, Suk-Ho;Lee, Young-Mock;Kang, Hoon-Chul;Lee, Joon-Soo;Kim, Heung-Dong
    • Clinical and Experimental Pediatrics
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    • 제53권12호
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    • pp.994-999
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    • 2010
  • Purpose: Mitochondrial dysfunction can present with various symptoms depending on the organ it has affected. This research tried to analyze the ophthalmologic symptoms and ophthalmologic examination (OE) results in patients with mitochondrial disease (MD). Methods: Seventy-four patients diagnosed with mitochondrial respiratory chain complex defect with biochemical enzyme assay were included in the study. They were divided into 2 groups based on the OE results by funduscopy and were analyzed on the basis of their clinical features, biochemical test results, morphological analysis, and neuroimaging findings. Results: Thirty-seven (50%) of the 74 MD patients developed ophthalmologic symptoms. Abnormal findings were observed in 36 (48.6%) patients during an OE, and 16 (21.6%) of them had no ocular symptoms. Significantly higher rates of prematurity, clinical history of epilepsy or frequent apnea events, abnormal light microscopic findings in muscle pathology, diffuse cerebral atrophy in magnetic resonance imaging, and brainstem hyperintensity and lactate peaks in magnetic resonance spectroscopy were noted in the group with abnormal OE results. Conclusion: Although the ophthalmologic symptoms are not very remarkable in MD patients, an OE is required. When the risk factors mentioned above are observed, a more active approach should be taken in the OE because a higher frequency of ocular involvement can be expected.

Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

  • De Molon, Rafael Scaf;Morais-Camillo, Juliana Aparecida Najarro Dearo;Sakakura, Celso Eduardo;Ferreira, Mauricio Goncalves;Loffredo, Leonor Castro Monteiro;Scaf, Gulnara
    • Imaging Science in Dentistry
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    • 제42권4호
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    • pp.243-247
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    • 2012
  • Purpose: This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Materials and Methods: Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. Results: There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm ($IC_{95%}$:6.04-6.54) and 6.79 mm ($IC_{95%}$:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm($IC_{95%}$:6.40-6.89) and 6.79mm($IC_{95%}$:6.45-7.11), respectively. Conclusion: The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

Light-emitting diode assessment of dentinal defects: the role of presumed extraction forces

  • Coelho, Marcelo Santos;Card, Steven J.;Tawil, Peter Z.
    • Restorative Dentistry and Endodontics
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    • 제42권3호
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    • pp.232-239
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    • 2017
  • Objectives: The evaluation of iatrogenic dentinal defects in extracted teeth may be influenced by extraction forces and prolonged dry times. The purpose of this study was to compare the presence of dentinal defects in freshly extracted, periodontally compromised teeth with those in a group of teeth with uncontrolled extraction forces and storage time. Materials and Methods: The experimental group consisted of eighteen roots obtained from teeth extracted due to periodontal reasons with class II or III mobility. They were kept in saline and sectioned within 1 hour following extraction. The control group consisted of matched root types obtained from an anonymous tooth collection, consistent with previous dentinal defect studies. The slices were obtained at 3, 6, and 9 mm from the apex. The imaging process exposed all specimens to no more than 60 seconds of dry time. The ${\times}12.8$ magnification was used for the 9 mm slices and ${\times}19.2$ magnification for the 3 mm and 6 mm slices under light-emitting diode (LED) transillumination. The root canal spaces and periodontal tissues were masked to minimize extraneous factors that might influence the evaluators. Chi-square test was used for statistical analysis. Results: Dentinal defects were detected in 17% of the experimental group teeth, compared to 61% of control teeth (p = 0.015). Conclusions: LED transillumination assessment of freshly extracted roots with class II or III mobility showed smaller number of dentinal defects than roots with uncontrolled storage time and extraction forces. The use of freshly extracted roots with mobility should be considered for future dental defect assessment studies.

Strut Support with Tricortical Iliac Allografts in Unstable Proximal Humerus Fractures: Surgical Indication and New Definition of Poor Medial Column Support

  • Lee, Seung-Jin;Hyun, Yoon-Suk;Baek, Seung-Ha
    • Clinics in Shoulder and Elbow
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    • 제22권1호
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    • pp.29-36
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    • 2019
  • Background: The execution of fibular allograft augmentation in unstable proximal humerus fractures (PHFs) was technically demanding. In this study, the authors evaluated the clinical and radiographic outcomes after tricortical iliac allograft (TIA) augmentation in PHFs. Methods: We retrospectively assessed 38 PHF patients treated with locking-plate fixation and TIA augmentation. Insertion of a TIA was indicated when an unstable PHF showed a large cavitary defect and poor medial column support after open reduction, regardless of the presence of medial cortical comminution in preoperative images. Radiographic imaging parameters (humeral head height, HHH; humeral neck-shaft angle, HNSA; head mediolateral offset, HMLO; and status of the union), Constant score, and range of motion were evaluated. Patients were grouped according to whether the medial column support after open reduction was poor or not (groups A and B, respectively); clinical outcomes were compared for all parameters. Results: All fractures healed radiologically (average duration to complete union, 5.8 months). At final evaluation, the average Constant score was 73 points and the mean active forward flexion was $148^{\circ}$. Based on the Paavolainen assessment method, 33 patients had good results and 5 patients showed fair results. The mean loss of reduction was 1.32 mm in HHH and 5.02% in HMLO. None of the parameters evaluated showed a statistically significant difference between the two groups (poor and not poor medial column support). Conclusions: In unstable PHFs, TIA augmentation can provide good clinical and radiological results when there are poor medial column support and a large cavitary defect after open reduction.

Determination of the optimal diabetes duration for bone regeneration experiments in an alloxan-induced diabetic rabbit calvarial defect model

  • Jeong, Sang-Hun;Jung, Bo Hyun;Yoo, Ki-Yeon;Um, Heung-Sik;Chang, Beom-Seok;Lee, Jae-Kwan;Choi, Won-Youl
    • Journal of Periodontal and Implant Science
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    • 제48권6호
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    • pp.383-394
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    • 2018
  • Purpose: The purpose of this study was to evaluate the optimal diabetes duration for bone regeneration experiments in an alloxan monohydrate (ALX)-induced diabetic rabbit calvarial defect model by evaluating the association between diabetes duration and bone healing capacity. Methods: Twenty-four New Zealand white rabbits were used. Twenty-two rabbits were injected with 100 mg/kg of ALX to induce experimental diabetes. These rabbits were divided into 4 groups, including a control group and groups with diabetes durations of 1 week (group 1), 2 weeks (group 2), and 4 weeks (group 3). Calvarial defects were created at 1, 2, and 4 weeks after ALX injection and in the control rabbits. Cone-beam computed tomography (CBCT) scanning was performed on the day of surgery and at 2 and 4 weeks after surgery. The rabbits were sacrificed 4 weeks after surgery, followed by histological and immunofluorescence analysis. Results: The diabetic state of all diabetic rabbits was well-maintained throughout the experiment. Reconstructed 3-dimensional CBCT imaging showed more rapid and prominent bone regeneration in the control group than in the experimental groups. Histological staining showed notable bone regeneration in the control group, in contrast to scarce bone formation in the experimental groups. The appearance and immunoreactivity of receptor activator of nuclear factor-kappa B and osteoprotegerin did not show notable differences among the groups. Conclusion: ALX administration at 100 mg/kg successfully induced experimental diabetes in rabbits. The effect of diabetes on bone healing was evident when the interval between diabetes induction and the intervention was ${\geq}1$ week.

심첨형 비후성 심근병증에서의 스트레스 부하 관류 자기공명영상 소견: 좌심실 벽 비후 정도와 지연 조영 증강 간의 관련성 (First-pass Stress Perfusion MR Imaging Findings of Apical Hypertrophic Cardiomyopathy: with Relation to LV Wall Thickness and Late Gadolinium-enhancement)

  • 유진영;전은주;김여군;최상일;최동주
    • Investigative Magnetic Resonance Imaging
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    • 제18권1호
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    • pp.7-16
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    • 2014
  • 목적: 심첨형 비후성 심근병증 환자에서 스트레스 부하 관류 자기공명영상을 통한 관류 결손의 빈도와 양상을 평가하고, 이를 좌심실 비대의 정도와 지연 조영 증강과 비교해 보고자 한다. 대상과 방법: 2008년 1월부터 2012년 12월까지 심초음파 및 심전도로 심첨형 비후성 심근병증을 진단받고, 스트레스 부하 관류, 영화 영상 및 지연 조영 증강 영상을 포함하는 심장 자기공명영상을 시행한 26명의 환자를 대상으로 하였다. 영화 영상에서 이완기 말에 416개 분절의 좌심실 벽 두께를 분석하였고 비후된 분절의 수와 연속하여 비후된 벽 분절의 수를 조사하였다. 또한 모든 환자에서 관류 결손과 지연 조영 증강의 유무를 평가하였다. 자기공명영상에서 관류 결손이 있을 경우, 산발형 혹은 고리형의 2가지 형태로 분류하였다. 단변량 분석을 통해 전체 관류 결손과 고리형 관류 결손에 대한 독립 변수를 산출하였다. 결과: 심첨형 비후성 심근병증의 76.9%(20명)에서 스트레스 부하 관류 자기공명영상시 관류 결손을 보였으며 이중 60% (12명)이 고리형 관류 결손을 보였다. 전체 관류 결손에 대한 독립 변수는 최대 좌심실 벽 두께와 비후된 분절의 수 였고 (p < 0.05), 고리형 관류 결손에 대한 독립 변수는 3개 이상의 연속한 비후된 분절의 수가 추가되었다. 그러나 지연 조영 증강은 관류결손과는 유의한 상관관계가 없었다. 결론: 심첨형 비후성 심근병증 환자의 4분의 3에서(75%) 관류 결손을 보였으며, 대부분이 고리형 관류 결손 형태를 보였다. 좌심실 벽의 비후 정도와 분포는 관류 결손의 형태와 관련이 있었지만 지연 조영 증강과는 유의한 상관성이 없었다. 따라서 심첨형 비후성 심근병증 환자군에서 관류 결손의 임상적 의미는 비심첨형 비후성 심근병증 환자군에서 보이는 관류결손과는 임상적 의의가 다를 것으로 보이며, 이에 대한 추후의 비교연구가 필요할 것으로 여겨진다.

개에서 요추부 척수를 압박하는 척추 골육종 발생례 (Vertebral Osteosarcoma Causing Compression of the Lumbar Spinal Cord in a Dog)

  • 강병재;류학현;박성수;;성규진;김용선;박준원;김완희;윤정희;김대용;권오경
    • 한국임상수의학회지
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    • 제27권5호
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    • pp.588-592
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    • 2010
  • 15년 령의 중성화 수컷 요크셔 테리어가 양측 후지의 보행 장애로 내원하였다. 5개월 전부터 후구 부전마비가 시작되어 점점 진행되었고, 4일 전부터는 증상이 빠르게 악화되었다. 후구 부전마비를 일으킬 수 있는 신경 질환을 감별하기 위해 컴퓨터 단층 촬영과 자기 공명 영상이 실시되었다. 컴퓨터 단층 촬영을 통해 4번 요추의 골 결손과 인접 부위의 연부 조직 종괴를 확인하였다. 자기 공명 영상을 통해서는 4번 요추의 왼쪽에서 T1강조 영상에서의 등신호종괴와 T2강조 영상에서의 고신호 종괴가 척수를 압박하는 것을 확인하였다. T1강조 영상에서 조영제 주입 후 종괴의 신호가 균일하게 증가하였다. 종괴의 절제 후 통증은 완화되었다. 조직병리학적 검사를 통해 병변이 척추 골육종임을 확인하였다. 컴퓨터 단층 촬영과 자기 공명 영상은 개에서 척추 골육종을 진단하고 수술적 제거를 위한 계획을 세우는데 유용하게 이용될 수 있다.

Creutzfelt Jacob Disease 의증 환자에 대한 임상보고 (A Case Study of the Creutzfelt Jacob Disease Suspected Patient)

  • 이희승;강태곤;김정주;한경석;배효상;박성식
    • 사상체질의학회지
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    • 제18권2호
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    • pp.139-147
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    • 2006
  • 1. Objectives Creutzfelt Jacob Disease is one of a group of neurodegenerative disorders causing spongiform encephalopathies due to a infection of prion or unconventional slow virus on central nerve system. The diagnosis of this disease is not easy and there is currently no cure. This article is to report our case about a female patient who was not diagnosed as CJD at the early period so that we treated her with Yangkyuksanhwa-tang(凉膈散火湯) and Jihwangbaekho-tang(地黃白虎湯). 2. Methods Magnetic resonance imaging(brain MRI), blood test and computer tomography were performed. The treatment for this patient was clinically based on Sasang Constitutional Medicine. 3. Results and Conclusions (1) Visual field defect, ataxia, myoclonus, sweating and dysuria were the main symptoms of the patient. (2) The pathological change in parenchyme was not revealed during the early periods by MR imaging. So the diagnosing CJD was not possible during the time in this case. (3) Jihwangbaekho-tang(地黃白虎湯) improved her myoclonus and sweating. Bur her mental disorder and the progress of the pathological change in the parenchyme was not able to be treated.

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Comparison between different cone-beam computed tomography devices in the detection of mechanically simulated peri-implant bone defects

  • Kim, Jun Ho;Abdala-Junior, Reinaldo;Munhoz, Luciana;Cortes, Arthur Rodriguez Gonzalez;Watanabe, Plauto Christopher Aranha;Costa, Claudio;Arita, Emiko Saito
    • Imaging Science in Dentistry
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    • 제50권2호
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    • pp.133-139
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    • 2020
  • Purpose: This study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles. Materials and Methods: Twenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient. Results: High intraobserver and interobserver agreement was found (P<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts. Conclusion: Within the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.