• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.355-361
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• 2014

The aim of the present study was to evaluate a relative emission of image plate (IP) in computed radiography (CR) system by using relative sensitivity in film/screen methods. The characteristic curve was obtained by using the uniform aluminum 11-step wedge penetrometer. X-ray exposure factors on radiographic digital image were 50 kVp, 10 mAs. We adjusted zero of all parameter of algorithms (MUSICA) so proximate to raw data and applied to 200 of exposure class. Modeling on relative emission of IP are used IP without fading time and IP after 4 hours, 8 hours, 12 hours, 24 hours in the respective storage after X-ray exposure. The results of this study showed that the sensitivity point density at the measuring of relative sensitivity in CR was suited pixel values of the 2000 easy to relatively measure the characteristic curve and when relative sensitivity is decreased, the amount of light emitted from the image signal for generating was also decreased. In conclusion, the proposed method of measurement of relative sensitivity can be utilized to evaluate the quantity of relative emission of IP in CR system.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.123-128
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• 2005

It is necessary to obtain images of high diagnosis worth based on ability and skill of radiological technologist in case of acquisition of medical radiologaphy information. In addition, we need the various kinds of education considering individual radiological technologist variation and the organization of clinical education according to the large amount of learning and more expensive knowledge of radiology. In this paper, we implement CAI system for cervical vertebrae fracture radiograph with multimedia authoring tools on web environments. The CAI system can train a new radiological technologist and study a lot of radiological technologist on the cervical vertebrae fracture radiography acquisition based on more objective and systematical data in radiography room. The proposed CAI system is also expected as a useful program which can help to cure patients based on accurate diagnosis as well as obtain radiography more quickly using a technology of radiography acquisition for cervical vertebrae fracture.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.271-275
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• 2018

It is possible to do not use the Image Plate for a long time in the clinic. for the acquisition of reliable images the decommissioning process is very important. In this study, we would like to look at complex noises that may occur during Image Plate use depending on the frequency and time of day. first, we got the image from computer radiography. second, We calculate the noise changes using Peak Signal to Noise Ratio(PSNR) and Noise Power Spectrum(NPS). finally, we suggest that remove the noise from the IP for more than 4 hours. and It turned out to be better to remove the noise more than once. this study will be a quantitative reference for Image Plate management and use in the clinical trial.

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.132-133
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• 2011

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.390-393
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• 2013

This case study describes the imaging features of radiography and computed tomography (CT) in four small breed dogs with lung lobe torsion. The medical records, thoracic radiographs and CT images of four dogs with confirmed lung lobe torsion were retrospectively reviewed. Pleural effusion and increased lobar opacity/density were seen on all CT and thoracic radiography in all four dogs. CT revealed narrowed/collapsed bronchus in all four dogs, while this was only appreciated on one thoracic radiography. The vesicular emphysema pattern was seen on four CT but only on three radiographic examinations. The specific findings of lung lobe torsion were vesicular emphysema and a narrowed/collapsed bronchus. These findings were more easily recognized on CT than with thoracic radiographs.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.123-129
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• 2023

The purpose of this study was to analyze differences in imaging quality and dose difference between intra-venous (IV) and intra-arterial (IA) liver dynamic computed tomography (CT). Herein, retrospective, blinded analysis was conducted to analyze signal-to-noise and contrast-to-noise ratios in cases of patients who underwent IV or IA liver dynamic CT for transarterial chemoembolization (TACE), an interventional procedure for hepatocellular carcinoma. The dose length product (DLP) value stored in Picture Archive and Communication System (PACS) was used to calculate the effective dose and thereby compare differences in the dose between the two methods. The mean liver and spleen signal to noise ratio (SNR) was greater in IV-liver dynamic CT than in IA-liver dynamic CT; however, contrast to noise ratio (CNR) was higher in IA-liver dynamic CT than in IV-liver dynamic CT. However, there were no differences in DLP and effective dose between the two methods. In conclusion, our findings showed that IA-liver dynamic CT showed a similar effective dose and superior CNR compared with IV-liver dynamic CT. Further studies must analyze 3D angiography CT of the hepatic artery to clearly distinguish the feeding artery, which is the essential step in interventional procedures for hepatocellular carcinoma.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.273-279
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• 2013

The purpose of the study was to present basic data to evaluation of the spatial resolution for exposure class(EC) in computed radiography(CR) by using the modulation transfer function(MTF). In this study, MTF was measured the edge method by using image plate(IP) of $100{\mu}mm$ pixels. A standard beam quality RQA5 based on an international electro-technical commission(IEC) standard was used to perform the X-ray imaging studies. Digital imaging began to set the sensitivity to EC 50, 100, 200, 300, 400, 600, 800, 1200 in X-ray irradiated to IP. The MTF 50% and 10% in the final images was analysis by using an authorized image analysis program the Origin 8.0 and the image J. As a results, the EC 200 was the best spatial resolution at MTF 50% ($1.979{\pm}0.114lp/mm$) and MTF 10% ($3.932{\pm}0.041$). Therefore, the EC 200 could be useful for the diagnosis of diseases that require high spatial resolution such as fractures.

• Journal of radiological science and technology
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• v.46 no.4
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• pp.295-301
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• 2023

In addition to protocol adjustments during CT examinations, the height of the CT table can also affect image quality. Therefore, this study aimed to investigate the change in image quality depending on the height of the table in brain CT, which accounts for a large proportion of CT examinations, by measuring signal to contrast to noise ratio (CNR) and noise power spectrum (NPS) using the head phantom and evaluating them. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. The CNR result showed the highest value at 965 mm, which is the height adjacent to the center of the head phantom. NPS showed the lowest NPS at 915 mm, the center of the head phantom in the low frequency region. From these results, it can be seen that the height of the table in CT examination is closely related to the image quality, and it can be seen the characteristics of image quality according to CT table through quantitative evaluation methods such as CNR and NPS.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.465-467
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• 2019

본 논문에서는 영상생성이 가능한 딥러닝 네트워크를 이용하여 조영증강 CT 영상을 획득하는 연구를 수행하였다. CT는 고해상도 영상을 바탕으로 환자의 질병 및 암 세포 진단에 사용되는 의료영상 기법 중 하나이다. 특히, 조영제를 투여한 다음 CT 영상을 획득되는 영상을 조영증강 CT 영상이라 한다. 조영증강된 CT 영상은 물질의 구성 성분의 영상대비를 강조하여 임상의로 하여금 진단 및 치료반응 평가의 정확성을 향상시켜준다. 하지많은 수의 환자들이 조영제 부작용을 갖기 때문에 이에 해당되는 환자의 경우 조영증강 CT 영상 획득이 불가능해진다. 따라서 본 연구에서는 조영증강 영상을 얻지 못하는 환자 및 일반 환자의 불필요한 방사선의 노출을 최소화 하기 위하여 영상생성 딥러닝 기법을 이용하여 CT 영상에서 조영증강 CT 영상을 생성하는 연구를 진행하였다. 영상생성 딥러닝 네트워크는 generative adversarial network (GAN) 모델을 사용하였다. 연구결과 아무런 전처리도 거치지 않은 CT 영상을 이용하여 영상을 생성하는 것 보다 히스토그램 균일화 과정을 거친 영상이 더 좋은 결과를 나타냈으며 생성영상이 기존의 실제 영상과 영상의 구조적 유사도가 높음을 확인할 수 있다. 본 연구결과 딥러닝 영상생성 모델을 이용하여 조영증강 CT 영상을 생성할 수 있었으며, 이를 통하여 환자의 불필요한 방사선 피폭을 최소하며, 생성된 조영증강 CT 영상을 바탕으로 정확한 진단 및 치료반응 평가에 기여할 수 있을거라 기대된다.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.407-414
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• 2014

The aim of the present study was to carry out quantitative analysis of spatial resolution for the influence of the focus size and digital image post-processing on the Computed Radiography (CR). The modulation transfer functions of an edge measuring method (MTF) was used for the evaluation of the spatial resolution. The focus size of X-ray tube was used the small focus (0.6 mm) and the large focus (1.2 mm). We evaluated the 50% and 10% of MTF for the enhancement of edge and contrast by using multi-scale image contrast amplification (MUSICA) in digital image post-processing. As a results, the edge enhancement than the contrast enhancement were significantly higher the spatial resolution of MTF 50% in all focus. Also the spatial resolution of the obtained images in a large focus were improved by digital image processing. In conclusion, the results of this study should serve as a basic data for obtain the high resolution clinical images, such as skeletal and chest images on the CR.