• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.63-71
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• 2012

This study aimed to evaluate the accuracy of breast cancer diagnosis of digital mammography which is in the highest interest of breast imaging test, and to investigate the characteristics of breast cancer patients. For this purpose, 57 breast cancer patients who underwent breast imaging test were examined between May 2010 and June 2011. The average age of the breast cancer patients was 50.8 years old, and the most frequently occurring location was the upper outer quadrant (UOQ), accounting for 33.3%. By age, the highest occurrence rate of breast cancer was the age group of 40~49, accounting for 42.1%. As for the breast composition of the breast cancer patients, fatty breast accounted for 31.6% (18/57) and dense breast for 68.4% (39/57), indicating that nearly 70% of the breast cancer patients have dense breast. It was found that the detection rate of breast cancer was the highest (45.3%) when both microcalcification and mass are simultaneously present in the radiographic lesion of the breast imaging. In dense breast, the mass without microcalcification was lower in detection rate than fatty breast. Accordingly, the mass is the cause of raising the false negative rate in dense breast. The findings show that the false negative rate of digital mammography was 7.0% and the sensitivity 93.0%. Also, the false negative rate of dense breast was 12.8%, and the sensitivity 87.2%, indicating that the sensitivity to breast cancer in this study was higher than the dense breast of previously reported screen film mammography.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.639-646
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• 2017

The purpose of this study is to present the algorithm to minimize the image noise caused by deterioration of high X-ray container inspection equipment and the faulty detection sensors, and to improvement quality of the container inspection images using MATLAB Toolbox. The daily checking images for the container inspection were used with the subject images and the noise caused by the horizontal and vertical images was evaluated with Root Mean Square (RMS) method, which is the most basic evaluation method of digital radiation image. Also, quality of the improved images was evaluated compared to quality of the orignal images. As a result, all RMS value of the improved images was lower then the original images by a mean of 13.5% in the horizontal images and 18.2% in the vertical images respectively. Also so did RMS value of the improved container images, by a mean of 13.4% in the horizontal images and 19.1% in the vertical images respectively. These findings can be verified objectively and visually and they would help the reading process of the container images be effective in Korea Customs Service.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1057-1065
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• 2023

Non-invasive liver fibrosis diagnosis is crucial for patients with chronic liver diseases. Many patients cannot undergo liver tissue biopsy, so predicting the degree of liver fibrosis early through meaningful methods can reduce complications related to chronic liver diseases, such as liver cell carcinoma and cirrhosis. This study compared and analyzed the quantitative measurement of liver fibrosis using shear wave elastography in conjunction with liver ultrasound findings and their associations with serum biomarkers (p<0.05). The results showed that the shear wave elastography measurement in the normal group was 4.55 ± 0.69 kPa, while the abnormal contrast group with echogenic patterns had a measurement of 8.27 ± 1.83 kPa. The hepatitis B carrier group exhibited higher shear wave elastography measurements, and among serum biomarkers, AST, ALT, GGT, and PT showed statistically significant positive correlations with fibrosis severity according to SWE categories (p<0.05), while ALP and TB did not demonstrate statistically significant differences (p=0.163, p=0.567). Conversely, Albumin and PLT showed significant negative correlations (p<0.05). Clinically, utilizing shear wave elastography measurements through liver ultrasound in the tracking and repeat testing of liver fibrosis in chronic hepatitis B patients without cirrhosis can assist in achieving more objective diagnoses among healthcare providers.

• Journal of the Korean Society of Radiology
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• v.18 no.4
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• pp.355-363
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• 2024

This study evaluated the clinical utility of Shear Wave Elastography(SWE) by analyzing the differences in elastic modulus and shear wave speed across various types of breast tissue and assessing inter-observer agreement. A breast phantom that included normal breast tissue, benign tumors, and malignant tumors was utilized, and ten radiologists participated, measuring the minimum, average, and maximum elastic modulus and shear wave speed for each tissue type. Analysis of differences between tissues was conducted using one-way ANOVA, and intra- and inter-observer agreement was assessed using the Intraclass Correlation Coefficient(ICC). The results demonstrated significant differences in the average values of elastic modulus and shear wave speed among the tissue types(p<0.001), with malignant tumor tissues showing the highest average values. Furthermore, the ICC analysis for elastic modulus ranged from 0.75 to 0.99 and for shear wave speed from 0.89 to 0.99, indicating high reproducibility and agreement. These findings suggest that SWE is a reliable tool with high reproducibility and specificity for the diagnosis of breast cancer.

• Journal of the Korean Society of Radiology
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• v.18 no.4
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• pp.373-381
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• 2024

This study aimed to identify and assess the influence of risk factors on the frequency of thyroid nodules diagnosed through ultrasonography among adults visiting for health screenings. The study analyzed 210 adult men and women who underwent thyroid ultrasound at J Hospital in Busan. The differences in variables were analyzed using Chi-square and independent t-tests, and risk ratios were calculated using binary logistic regression. The results showed significant differences in gender, age, T3, Free T4, Uric acid, T-chol, HDL-C and LDL-C. The risk ratios for risk factors indicated that women had a 2.42 times higher risk compared to men, and the age groups 41-50 and over 61 had risks 2.32 and 2.22 times higher, respectively compared to those under 40. Conversely, and increase in T3 and Free T4 levels was associated with a decreased risk of 0.12 and 0.86 times, respectively, while lipid levels had negligible influence. Based on these findings, it is concluded that regular ultrasonography monitoring, rather than solely relying on biochemical markers, is crucial for the early detection and management of thyroid nodules.

• Journal of radiological science and technology
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• v.28 no.3
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• pp.211-217
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• 2005

This study obtained the following conclusions by analyzing whether or not thyroid nodule, the number of nodules depending on age and gender, and the developed site of nodule, targeting 838 persons in their 30s-70s who were conducted the thyroid ultrasonography, without clinical symptoms, at the Health Promotion Center. 1. As for the general characteristics of 838 research subjects, men were 368 persons(44%), and women were 470 persons (56%), and the mean age was 51. 2. Among 838 whole subjects, a case, which was diagnosed to be normal, was 590 persons(70%), and persons with nodules findings were 248 persons (30%), thus it was indicated 30% on an average in having the thyroid nodules findings. 3. As for the frequency by age level in thyroid nodule, it was represented men with 10%-14% and women with $20{\sim}29%$ in their $30{\sim}40s$, and men with $27{\sim}33%$ and women with 37-52% in their 50-60s, and men with 46% and women with 50% in their 70s. 4. As a result of obtaining 248 persons, who have thyroid nodules findings, with the solitary nodule and the multiple nodule, it was indicated the solitary nodule of 50.5% with 125 persons and the multiple nodule of 49.5%, thereby representing the almost same ratio. 5. As for the size of thyroid nodule, the majority in all the age levels had the nodule in small size, and the size of $1{\sim}10\;mm$ was largest with 187 persons (75%) among 248 persons with abnormal findings, and it was 45 persons (18%) in $11{\sim}20\;mm$, 14 persons (5.6%) in $21{\sim}30\;mm$, and 2 persons in more than 31 mm. 6. As for the anatomically developed site in nodule, it was indicated the right lobe with 93 persons (38%), the left lobe with 67 persons (27%), both lobes with 75 persons (30%), and isthmus with 13 persons (5.3%), thereby representing the largest frequency in the right lobe, and it was discovered less in isthmus.

• Journal of radiological science and technology
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• v.36 no.4
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• pp.313-318
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• 2013

Positron emission tomography/computed tomography (PET/CT) imaging with fluorodeoxyglucose (FDG) have been used as a powerful fusion modality in nuclear medicine not only for detecting cancer but also for staging and therapy monitoring. Nevertheless, there are various causes of FDG uptake in normal and/or benign tissues. The purpose of present study was to investigate whether additional delayed imaging can improve the diagnosis to differentiate the rates of FDG uptake at axillary lymph nodes (ALN) between malignant and benign in breast cancer patients. 180 PET/CT images were obtained for 27 patients with ALN uptake. The patients who had radiotherapy and chemotherapy were excluded from the study. $^{18}F$-FDG PET/CT scan at 50 min (early phase) and 90 min (delayed phase) after $^{18}F$-FDG injection were included in this retrospective study. The staging of cancers was confirmed by final clinical according to radiologic follow-up and pathologic findings. The standardized uptake value (SUV) of ALN was measured at the Syngo Acquisition Workplace by Siemens. The 27 patients included 18 malignant and 9 ALN benign groups and the 18 malignant groups were classified into the 3 groups according to number of metastatic ALN in each patient. ALNs were categorized less than or equal 3 as N1, between 4 to 9 as N2 and more than 10 as N3 group. Results are expressed as the mean${\pm}$standard deviation (S.D.) and statistically analyzed by SPSS. As a result, Retention index (RI-SUV max) in metastasis was significantly higher than that in non-metastasis about 5 fold increased. On the other hand, RI-SUV max in N group tended to decrease gradually from N1 to N3. However, we could not prove significance statistically in malignant group with ANOVA. As a consequence, RI-SUV max was good indicator for differentiating ALN positive group from node negative group in breast cancer patients. These results show that dual-time-point scan appears to be useful in distinguishing malignant from benign.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.209-217
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• 1999

Backgrounds: To investigate the role of CT as a screening tool and to compare the diagnostic accuracy with that of the fiberoptic bronchoscopy (FOB) in evaluating the causes of hemoptysis. Methods: The retrospective review of plain chest radiograph, CT and FOB was done in 72 patients with hemoptysis. The diagnosis were confirmed by histology (n=33), bacterial culture (n=6), cytology (n=3), serology (n=2), skin test (n= 1), clinical response (n=5), and airway disease mainly by HRCT (n=22). Results: The causes of hemoptysis were shown to be lung cancer (n=29), bronchiectasis (n=19), tuberculosis (n=12), aspergilloma (n=5), invasive aspergillosis (n=l), COPD (n=3) and others (n=3). The sensitivity was 100% and 91,7% by CT and FOB respectively. The diagnostic compatibility was 95.8% and 59.7% by CT and FOB respectively. The diagnostic compatibility in cases with central airway disease was 96.3% and 100 % in CT and FOB. In parenchymal disease, CT and FOB showed 91.3 % and 43.5 % of compatibility, respectively. airway disease, CT and FOB showed 100% and 31.8% compatibility, respectively. That is to say, CT has higher sensitivity and diagnostic compatibility than FOB for identifying the causes of hemoptysis, and is more helpful for patients with hemoptysis from parenchymal or airway disease. FOB had the advantage in obtaining histologic, cytologic and bacteriologic diagnosis with biopsy or washing Conclusion: CT should be used as the screening method before performing FOB for patients with hemoptysis who have normal or nonspecific findings or peripheral airway disease in plain chest radiograph.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.669-676
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• 2020

The purpose of this study was to analyze the changes in the values of Hounsfield Unit (HU) according to the changes in monoenergy (keV) and dilution ratio of the contrast agent, using the spectral CT. Spectral CT was used as the testing device, while 20 cc syringe phantom was used to set a total of six dilution ratios of the contrast agent: 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7. Here, the non-ionic iodine solution (350 mg/ml) was used as a contrast agent. The syringe axial image was reconstructed by adjusting the obtained data on nine MonoE levels; 40 keV, 45 keV, 50 keV, 55 keV, 60 keV, 65 keV, 70 keV, 75 keV, and 80 keV. The HU values were measured at the three points of the reconstructed syringe axial image. The measurements were taken 1,620 times in total. In the analysis of the HU values according to the changes in keV and dilution ratio of the contrast agent, the highest and lowest HU values were obtained from dilution ratio 8:2 and dilution ratio 3:7, respectively, across every MonoE in the comparison of HU according to dilution ratio per MonoE (p<0.05), while the highest and lowest HU values were obtained from 40 keV and 80 keV, respectively, across all dilution ratios in the comparison of HU according to MonoE per dilution ratio (p<0.05). For the correlation per each parameter, a negative correlation of -15.014 ± 0.298 was found for HU per keV (R²=0.519) and a negative correlation of -61.372 ± 3.608 was found for HU per dilution ratio (R²=0.152) (p<0.05). To conclude, an increase in keV or dilution ratio of the contrast agent was shown to decrease the HU, and the findings in this study are anticipated to serve as the basic data in the research of HU-related parameters in Spectral CT.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.597-602
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• 2016

Recent clinical field utilizes the aluminium filter in order to reduce the low-energy photons. However, the usage of the filter can cause adverse effect on the image quality because of the scattered dose that is generated by X-ray hardening phenomenon. Further, usage of filter with improper thickness can be a reason of dose creep phenomenon where unnecessary exposure is generated towards the patient. In this study, the author evaluated the RMS and the RSD analysis in order to have a quantitative evaluation for the effect of forward scattering dose by the filter on the image. as a result of the study, the FSR and the RSD was increased together with the increasing of thickness of the filter. In this study the RSD means the standard deviation of the mean value is relatively size. It can be understood that the signal-to-noise ratio decreases when the average value is taken as a signal and the standard deviation is judged as a noise. The signal-to-noise ratio can understanding as index of resolution at image. Based on these findings, it was quantitatively verified that there is a correlation of the image quality with the FSR by using an additional filter. The results, a 2.5 mmAl which is as recommended by NCRP in the tube voltage of 70 kVp or more showed the 14.6% on the RSD when the filter was not in used. these results are considered able to be utilized as basic data for the study about the filter to improve the quality of the image.