• Title/Summary/Keyword: quantitative computed tomography

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Quantitative analysis of hemothorax by computed tomography (흉부 전산화 단층촬영을 이용한 혈흉의 정량분석)

  • 강청희
    • Journal of Chest Surgery
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    • v.28 no.3
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    • pp.228-232
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    • 1995
  • Computed tomography[CT is an effective technique for the evaluation of the thorax following blunt trauma. To evaluate multiply injured 30 patients who were diagnosed as hemothorax in emergency room, computed tomography of thorax was done. The thickness of slice was one centimeter and the entire pleural cavity from the apex to the costophrenic angle was included in the evaluation. Integration and addition of the hemothorax area for each CT slice was made and amount of blood in the pleural cavity was estimated. The slice which showed largest area of hemothorax was selected and the height and width of the hemothorax area were measured. The number of slices which showed radiographic evidence of hemothorax was counted. Regression analysis was done and measured amount of hemothorax, the height and width of the hemothorax area for each slice and number of slices were put as variables. And following equation was derived. V=108.3A-0.8B-7.4C+84.7 [R2=0.74 [ V: amount of hemothorax, A: height, B: width, C: number of slices Total amount of blood from thoracic drainage was compared to the measured amount by computed tomography and the relation between the two values was statistically significant.[p=0.001 In conclusion, quantitative estimation of size of hemothorax was possible by the above equation and the process was very helpful for determination policy of treatment of individual patient.

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Application of Quantitative Assessment of Coronary Atherosclerosis by Coronary Computed Tomographic Angiography

  • Su Nam Lee;Andrew Lin;Damini Dey;Daniel S. Berman;Donghee Han
    • Korean Journal of Radiology
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    • v.25 no.6
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    • pp.518-539
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    • 2024
  • Coronary computed tomography angiography (CCTA) has emerged as a pivotal tool for diagnosing and risk-stratifying patients with suspected coronary artery disease (CAD). Recent advancements in image analysis and artificial intelligence (AI) techniques have enabled the comprehensive quantitative analysis of coronary atherosclerosis. Fully quantitative assessments of coronary stenosis and lumen attenuation have improved the accuracy of assessing stenosis severity and predicting hemodynamically significant lesions. In addition to stenosis evaluation, quantitative plaque analysis plays a crucial role in predicting and monitoring CAD progression. Studies have demonstrated that the quantitative assessment of plaque subtypes based on CT attenuation provides a nuanced understanding of plaque characteristics and their association with cardiovascular events. Quantitative analysis of serial CCTA scans offers a unique perspective on the impact of medical therapies on plaque modification. However, challenges such as time-intensive analyses and variability in software platforms still need to be addressed for broader clinical implementation. The paradigm of CCTA has shifted towards comprehensive quantitative plaque analysis facilitated by technological advancements. As these methods continue to evolve, their integration into routine clinical practice has the potential to enhance risk assessment and guide individualized patient management. This article reviews the evolving landscape of quantitative plaque analysis in CCTA and explores its applications and limitations.

Does Simultaneous Computed Tomography and Quantitative Computed Tomography Show Better Prescription Rate than Dual-energy X-ray Absorptiometry for Osteoporotic Hip Fracture?

  • Ko, Jae Han;Lim, Suhan;Lee, Young Han;Yang, Ick Hwan;Kam, Jin Hwa;Park, Kwan Kyu
    • Hip & pelvis
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    • v.30 no.4
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    • pp.233-240
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    • 2018
  • Purpose: This study aimed to evaluate the efficacy of simultaneous computed tomography (CT) and quantitative CT (QCT) in patients with osteoporotic hip fracture (OHF) by analyzing the osteoporosis detection rate and physician prescription rate in comparison with those of conventional dual-energy X-ray absorptiometry (DXA). Materials and Methods: This study included consecutive patients older than 65 years who underwent internal fixation or hip arthroplasty for OHF between February and May 2015. The patients were assigned to either the QCT (47 patients) or DXA group (51 patients). The patients in the QCT group underwent QCT with hip CT, whereas those in the DXA group underwent DXA after surgery, before discharge, or in the outpatient clinic. In both groups, the patients received osteoporosis medication according to their QCT or DXA results. The osteoporosis evaluation rate and prescription rate were determined at discharge, postoperative (PO) day 2, PO day 6, and PO week 12 during an outpatient clinic visit. Results: The osteoporosis evaluation rate at PO week 12 was 70.6% (36 of 51 patients) in the DXA group and 100% in the QCT group (P<0.01). The prescription rates of osteoporosis medication at discharge were 70.2% and 29.4% (P<0.001) and the cumulative prescription rates at PO week 12 were 87.2% and 60.8% (P=0.003) in the QCT and DXA groups, respectively. Conclusion: Simultaneous CT and QCT significantly increased the evaluation and prescription rates in patients with OHF and may enable appropriate and consistent prescription of osteoporosis medication, which may eventually lead to patients' medication compliance.

Correlation between gray values of cone-beam computed tomograms and Hounsfield units of computed tomograms: A systematic review and meta-analysis

  • Selvaraj, Abirami;Jain, Ravindra Kumar;Nagi, Ravleen;Balasubramaniam, Arthi
    • Imaging Science in Dentistry
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    • v.52 no.2
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    • pp.133-140
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    • 2022
  • Purpose: The aim of this review was to systematically analyze the available literature on the correlation between the gray values (GVs) of cone-beam computed tomography (CBCT) and the Hounsfield units (HUs) of computed tomography (CT) for assessing bone mineral density. Materials and Methods: A literature search was carried out in PubMed, Cochrane Library, Google Scholar, Scopus, and LILACS for studies published through September 2021. In vitro, in vivo, and animal studies that analyzed the correlations GVs of CBCT and HUs of CT were included in this review. The review was prepared according to the PRISMA checklist for systematic reviews, and the risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. A quantitative analysis was performed using a fixed-effects model. Results: The literature search identified a total of 5,955 studies, of which 14 studies were included for the qualitative analysis and 2 studies for the quantitative analysis. A positive correlation was observed between the GVs of CBCT and HUs of CT. Out of the 14 studies, 100% had low risks of bias for the domains of patient selection, index test, and reference standards, while 95% of studies had a low risk of bias for the domain of flow and timing. The fixed-effects meta-analysis performed for Pearson correlation coefficients between CBCT and CT showed a moderate positive correlation (r=0.669; 95% CI, 0.388 to 0.836; P<0.05). Conclusion: The available evidence showed a positive correlation between the GVs of CBCT and HUs of CT.

A Study on Spinal Bone Mineral Density Measured with Quantitative Computed Tomography (정량적 전산화 단층촬영법을 이용한 척추 골밀도 측정)

  • Yeo, Jin-Dong;Park, Jae-Seong
    • The Korean Journal of Health Service Management
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    • v.3 no.2
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    • pp.87-94
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    • 2009
  • The purpose of this study is to evaluate the relationship between osteoporotic postmenopausal women and its bone mineral density value by using the single energy quantitative CT. 1. Decreasing BMD with age is evident. There is a significant low BMD value in the osteoporotic women compared with the healthy subgroup. 2. BMD decrease from T12 to L4, except in healthy premenopausal women. 3. Relationship of spinal BMD expressed as average BMD of T12 through L4 Show strong correlation with mean BMD in all vertebral levels. 4. There are significantly different BMD value from T12 through L4 in subgroup 1, 2, 3 but there is no statistically significant difference between subgroup 2 and 3. Conclusion, There is a significant decreasing BMD with age but it is difficult to differentiate postmenopausal relatively healthy women from osteoporotic women by BMD.

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Improvement of signal and noise performance using single image super-resolution based on deep learning in single photon-emission computed tomography imaging system

  • Kim, Kyuseok;Lee, Youngjin
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2341-2347
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    • 2021
  • Because single-photon emission computed tomography (SPECT) is one of the widely used nuclear medicine imaging systems, it is extremely important to acquire high-quality images for diagnosis. In this study, we designed a super-resolution (SR) technique using dense block-based deep convolutional neural network (CNN) and evaluated the algorithm on real SPECT phantom images. To acquire the phantom images, a real SPECT system using a99mTc source and two physical phantoms was used. To confirm the image quality, the noise properties and visual quality metric evaluation parameters were calculated. The results demonstrate that our proposed method delivers a more valid SR improvement by using dense block-based deep CNNs as compared to conventional reconstruction techniques. In particular, when the proposed method was used, the quantitative performance was improved from 1.2 to 5.0 times compared to the result of using the conventional iterative reconstruction. Here, we confirmed the effects on the image quality of the resulting SR image, and our proposed technique was shown to be effective for nuclear medicine imaging.

Quantitative Analysis of Skarn Ore Using 3D Images of X-ray Computed Tomography (3차원 X-ray 단층 화상을 이용한 스카른 광석의 정량분석 연구)

  • Jeong, Mi-Hee;Cho, Sang-Ho;Jeong, Soo-Bok;Kim, Young-Hun;Park, Jai-Koo;Kaneko, Katsuhiko
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.3
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    • pp.211-217
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    • 2010
  • A micro-focus X-ray computed tomography (CT) was employed to determine quantitative phase analysis of skarn Zn-Pb-Cu ore by nondestructive visualization of the internal mineral distribution of a skarn ore. The micro CT images of the ore were calibrated to remove beam hardening artifacts, and compared with its scanning electron microscope (SEM) images to set the threshold of CT number range covering sulfide ore minerals. The volume ratio of sulfide and gangue minerals was calculated 20.5% and 79.5%, respectively. The quantitative 3D X-ray CT could be applied to analyse the distribution of economic minerals and their recovery.

Three-dimensional imaging modalities in endodontics

  • Mao, Teresa;Neelakantan, Prasanna
    • Imaging Science in Dentistry
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    • v.44 no.3
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    • pp.177-183
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    • 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.

A Study on the Quantification Error due to the Reconstruction Filters in Single Photon Emission Computed Tomography(SPECT) (단일광자방출 전산화단층촬영상에서 재구성 필터에 의한 정량화 오차에 관한 연구)

  • 곽철은;정준기
    • Journal of Biomedical Engineering Research
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    • v.12 no.1
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    • pp.43-48
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    • 1991
  • As the computerized methods and equipments In nuclear medicine imaging increases, quantitative information is needed on the single photon emission computed tomographic Images as well as on the conventional nuclear medicine images. In this paper, the authors investigated the effect of several clinician - friendly reconstrution filters on the resultant transverse slices of backprojected Profiles of radioisotope distribution from the Quantitative point of view, and reduced the filter parameters such as cutoff frequency and order of filter which are neces mary to minimize the quantification error using computer-generated phantoms.

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