• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.165-169
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• 2011

The purpose of this study is to compare the measurement result of radiation dose by using standard thoracic phantom and ionization chamber to advice proposal in the shooting condition of chest PA projection at hospitals recently. And to understand the change between radiation dose and resolution in different conditions. The period this study was from August 2010 to September 2010 and the subjects of the study was 3 general hospitals, 4 personal hospitals and 1 laboratory at the college. Finally we study with 6 DR, 1 CR, and 4 F/S equipments. Most hospitals met advice proposal, but some of the hospitals exceed advice dose from the result of our study. We can lower radiation dose about 25% when kVp is lowered about 20% in DR equipment. And we can lower radiation dose about 50% when mAs is lowered about 35%. The image quality was similar to the original in the study. Most hospitals which exceed advice dose were personal hospitals. The reason why it happened is that radiation dose for chest PA projection at personal hospitals is higher than general hospitals and the personal hospitals' equipments are older than general hospitals' equipments. We guess that patients' radiation dose of chest PA projection can be lowered from the result.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.1-6
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• 2018

The purpose of this study is to provide baseline data on lung field size measured radiological method by chest PA image in normal Korean. The subject of this study is 496 normal persons who performed chest PA examination using x-ray digital radiography system. The measurement method is from the apex of right and left lung to the costophrenic angle of both lung, from the top of the image to the lowest costophrenic angle of both lung and transverse line of the largest lung area. As a result of this study, the following conclusions were obtained. A lung field size of male is larger than the female(p<0.05). The younger the age, the longer both lung length and total lung height statistically significant. As a increase height and length, A lung field size was increased(p<0.05). But, BMI is not associated with a lung field size. This study will be data of reference data when radiological technologists perform chest PA examination.

• The Journal of the Korea Contents Association
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• v.2 no.4
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• pp.23-29
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• 2002

This paper suggest the image compression that is needed to process PACS in medical information system. The image decoding method is used Linear-predictor and Lloyd-Max quantizer(quantization) in the Wavelet transform domain. Wavelet Transform Method is processed the multi-resolution by dividing image into 10 sub-bands of 3 levels. Low frequency domain that is sensitive to human visual characteristic is encoded by DPCM which is lossless encoding methods, and Lloyed-Max quantizer, the optimal quantizer for reducing ringing and aliasing in the image of inter sub-band, is used in the remaining high frequency domain of sub-band. The examination verifies that decompressed images are superior by the result that PSNR is 28.53dB on the input image, 512$\times$152 abdominal CT image and Chest image.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.322-330
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• 2011

To compare of quality control for chest radiography between special examination (SEP) and medical institution for pneumoconiosis (MIP). For the first time, we had visited at 33 institutions (SEP; 17 institutions, MIP; 16 institutions) to evaluate the quality control of chest radiography which is used in diagnosis of patients with pneumoconiotic complications. Image quality was rated by two experienced chest radiologists, and evaluated for radiological technique (RT), reading environment (RE) and image quality (IQ) between SEP and MIP according to the guideline published by OSHRI. Generator capacity, used duration and modality of chest radiography equipment were not signigicant difference between SEP and MIP, but there were signigicant difference in tube voltage and grid ratio used for chest radiography except to tube current and exposure time. SEP was statistically significant higher in RT (71.2 vs. 54.5, p=0.015), RE (78.8 vs. 51.5, p=0.007) to MIP, but not significant difference in IQ (64.8 vs. 59.3, p=0.180). For reliable and precisional diagnosis of patients with pneumoconiotic complications, the MIP requires the evaluation and education of quality control for improving chest radiography.

• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.467-471
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• 2015

This study's purpose is improve image quality to keep accurate tube angle in order to recognize distortion degree conditions by patient's position or tube angle and to provide exact clinical informations when taking chest AP projection for patient which have L-tube in stomach. The experimental equipment was ELMO-T6S by SHIMADZU corporation, then we put L-tube which attached 1 mm gap scales ruler on chest phantom surface. The experiment set by 90 kVp, 4 mAs, 120 cm distance. Each phantom position which changed supine, 30degree, 45degree, 60degree on the table exposured direct, ${\pm}5degree$, ${\pm}10degree$, ${\pm}15degree$ to head and feet directions. As a result, L-tube tip's position was changed by patient's position and tube angle. When patient's position is supine, tip's position change was lower than 30degree, 45degree, 60degree. We have to adjust patient's position or tube angle in order to occur image distortion by fault tube angle when confirming correct position L-tube tip through chest x-ray. Also, Radiological technologist try to make accurate evaluation index for satisfied L-tube insertion.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.455-461
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• 2021

Cardiomegaly is one of the most common diseases seen on chest X-rays, but if it is not detected early, it can cause serious complications. In view of this, in recent years, many researches on image analysis in which deep learning algorithms using artificial intelligence are applied to medical care have been conducted with the development of various science and technology fields. In this paper, we would like to evaluate whether the Inception V3 deep learning model is a useful model for the classification of Cardiomegaly using chest X-ray images. For the images used, a total of 1026 chest X-ray images of patients diagnosed with normal heart and those diagnosed with Cardiomegaly in Kyungpook National University Hospital were used. As a result of the experiment, the classification accuracy and loss of the Inception V3 deep learning model according to the presence or absence of Cardiomegaly were 96.0% and 0.22%, respectively. From the research results, it was found that the Inception V3 deep learning model is an excellent deep learning model for feature extraction and classification of chest image data. The Inception V3 deep learning model is considered to be a useful deep learning model for classification of chest diseases, and if such excellent research results are obtained by conducting research using a little more variety of medical image data, I think it will be great help for doctor's diagnosis in future.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.299-304
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• 2022

This study uses the 'S-align' function to present a reference value of the X-ray tube angle for the realization of an image similar to that of the chest PA image during chest AP radiography. This study targeted dummy phantom and used a 17"×17" DR image receptor. The irradiation conditions were 110 kVp, 160 mA, 50 ms, and the distance between the central X-ray and the image receptor was set to 180 cm and 110 cm, respectively. The end of the catheter was placed at the 11th thoracic height to indicate the nasogastric tube. In the case of lung apex length measurement, the mean value of measurement was 30.53±0.47 in PA. T 0°, TCA 5~25°, TCE 5~15° were 21.07±0.29, 27.60±0.21, 34.13±0.44, 39.86±0.31, 45.96±0.61 mm, 54.13±0.37 mm, 16.16±0.46 mm, 9.81±0.35 mm, 2.75±0.30 mm, respectively. For the depth of the catheter end, the average value measured at PA was 6.70±0.31 mm. T 0°, TCA 5~25°, TCE 5~15° were 15.72±0.38 mm, 24.10±0.50 mm, 29.24±0.86 mm, 34.35±0.35 mm, 41.06±1.08 mm, 48.07±0.38 mm, 12.85±0.25 mm, 7.92±0.36 mm, 3.01±0.39 mm, respectively. The length of the lung apex was similar to that of chest PA when the angle of incidence was adjusted from 5° to 10° in the leg direction, and the depth of the catheter tip was most similar when the X-ray tube angle was incident at 10° in the head direction. Therefore, To change the X-ray tube angle according to the purpose of the examination during the chest AP radiography using 'S-align' function is considered necessary.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.55-61
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• 2017

There are no recommended test conditions for digital photography in Chest PA examinations. However, each company recommends shooting examinations of the high voltage applied to the previous analog examination. The condition that satisfies the value of 200 ~ 800 which is the recommended Exposure Index value recommended by Philips was selected, and the dose was evaluated by Monte Carlo simulation, and the SNR and CNR were compared. As a result, it was possible to reduce the effective dose up to 77% by controlling the tube voltage, tube current, and additional filter, not the conventional high voltage imaging method. Although there were some differences according to the test conditions, the image evaluation results were similar to the images. We will compare the exposure dose according to changes in tube voltage, tube current, and additional filter at the digital chest radiograph and evaluate the image quality of the image to propose optimal conditions.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.819-825
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• 2023

In this study, among chest CT examination conditions, the tube voltage was changed to 100 and 80 kVp and the reconstruction algorithm was changed to FBP, ASIR-V, and DLIR to compare and analyze changes in examination dose and image quality. As a result, when applying ASIR-V and DLIR at a tube voltage of 100 kVp, which is lower than the existing tube voltage, the dose is lowered while achieving image quality most similar to that when applying 120 kVp and FBP. especially, DLIR reconstructed images had excellent SNR and CNR at all tube voltages. In addition, the SSIM index was analyzed to be closest to 1, showing the highest similarity to the original image. Therefore, when performing repeated chest CT examinations, the application of DLIR can reduce the examination dose by about 29.7%, which is expected to help solve some of the biggest problems with CT examinations, namely radiation exposure due to the examination.

• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.519-524
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• 2018

Chest examinations and mass chest examinations using the CR(computed radiography) System are frequently used clinically. a factor that degrades image quality in the acquisition process is the use of unused IPs long times. this paper addresses the estimation of winer filter and improved wiener filter to restoration of Chest CR images Experimental results show that the proposed method can reduce noise. in low noise variation image wiener method was excellent than improved method and the result was the opposite at high noise varience. the application of algorithms to chest CR images effectively eliminates noise. the classic Wiener filter was better than the improved method. Multiple patients examined during the process without any erase IP(image plate) process, The proposed algorithm determines that the images can be restored to a good quality and will help to read the images.