• Progress in Medical Physics
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• v.24 no.3
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• pp.176-182
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• 2013

Through this research, we measure the data for several SUVs such as SUVLBM, SUVBW, and SUVBSA using volume of interest in order to enhance the diagnostic level in whole-body image for healthy examinees via F-18 FDG PET/CT. Maximum value, mean value, standard deviation, and threshold value for each SUVs are shown. The measurement of SUVs are carried out with 31 examinees who have taken whole-body examination with F-18 FDG PET/CT from July, 2012 to August, 2012. To secure the preciseness of measurement, we selected 26 healthy examinees as a subject of measurement according to diagnostic view of a nuclear-medical doctor. We see from the measurement of SUVs of PET/CT that the value of SUVBW is hightest and followed by SUVLBM and SUVBSA in turn regardless of the use of contrast media. By comparing the SUVLBM-maximum data for the group used contrast media with those for the group used no contrast media, there found a trend that the measured values increase when the contrast media are used. Among them, liver, aorta, lumbar-5, and Cerebellum exhibit significant difference (p<0.05). We conclude that our data for SUVs would be basic references in overall image interpretation, and hope that the research using VOI would be active.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.519-526
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• 1996

Background : Clinical and Radiographic studies to differentiate benign from malignant pulmonary nodules have previously focused on clinical status and the morphologic and the computed tomographic attenuation characteristics of the lung nodules. Distinctive differences in the vascularity and pathophysiology of malignant versus benign pulmonary nodules were identified. We evaluated the diagnostic method for differentiating malignant from benign solitary pulmonary nodule by contrast enhancement on the spiral CT. Method : Sixteen patients with solitary pulmonary nodule were examined(Tuberculoma 8, primary lung cancer 8). Serial thin section on the spiral CT was performed before and after(45second, 2min, 5min) the onset of the injection of 100mL of nonionic contrast material(2mL/sec). Results : There was no difference in size of nodule and pre-contrast CT number (Hounsfield unit) between benign and malignant nodules. At forty-five second after the onset of the injection, malignant neoplasms($19.6{\pm}7.9$ HU) enhanced significantly more than tuberculomas($4.9{\pm}9.4$ HU, p=0.008). At 2minute and 5 minute after, malignant neoplasms($34.0{\pm}19.2$HU, $34.0{\pm}15.4$HU) enhanced significantly more than tuberculomas ($6.7{\pm}9.7$HU, p=0.007 and $7.7{\pm}11.5$HU, p=0.011). On cut-off value 20HU(contrast enhancement) 2minute after the injection of contrast media, sensitivity was 87% and specificity was 87%. No correlation between the contrast enhancement and size of the nodules was observed. Conclusion : Studies with the use of an intravenously administered noniodinated contrast medium in examining the enhancement properties of lung nodules was performed. The contrast enhancement was useful in differential diagnosis of solitary pulmonary nodules.

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.190-190
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• 2003

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.145-152
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• 2006

Radiographic contrast medium may cause tissue injury by extravasation during intravenous automated injection during CT examination. A large - volume extravasation (140 mL) occurred in an adult during contrast-enhanced CT The patient had a swelling and injury on the dorsum right hand of intravenous catheter region. The extravasation injury site was determined by CT scanning. The extavasation compartment syndrome case was examined using four separate display techniques. These 3D MDCT findings might help to determine the best course of treatment for patient with contrast extravasation. 3D image reconstructions provide accurate views of high-resolution and soft-tissue imaging. This paper introduces extravasation with the radiography and 3D MDCT findings.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.381-389
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• 2007

The purpose of this study is investigation of radiation dose in CT scan. Data were collected from various references and organizations. Doses measured by CT scanners of each medical organization were analyzed and they were calculated through the examination protocol. The results are as follows : 1. $CTDI_W$ value per 100mAs measured by Head Phantom was the highest in <4-slice MDCT scanner> of 24.20 mGy. $CTDI_W$ values were significantly different among scanner generations(p < 0.01). 2. $CTDI_W$ value per 100 mAs measured using body phantom was the highest in <4-slice MDCT scanner> of 13.58 mGy and the $CTDI_W$ values were significantly different among scanner generations(p < 0.01). 3. When contrast medium was not used, the highest scanner was <16 slice MDCT> of $818.83\;mGy{\codt}cm$ in exposure dose in brain scan(p < 0.05). When the contrast medium was used, the highest scanner was <4 slice MDCT> and its average was $1,460.77\;mGy{\cdot}cm$(p < 0.1). 4. When the contrast medium was not used, the highest scanner was <16-slice MDCT> of $521.63\;mGy{\cdot}cm$ on average in terms of the exposure dose in chest inspection(p<0.05). when the contrast medium was used, the highest scanner was found in 8 slice MDCT scanner and its average was $1,174.70\;mGy{\cdot}cm$. There was no statistically significant difference among scanners. 5. When the contrast medium was not used, the highest scanner was <16-slice MDCT> and its average was $856.27\;mGy{\cdot}cm$ in exposure dose on the abdomen-pelvis(p<0.05). when the contrast medium was used, the highest scanner was <16-slice MDCT> and its average was $1,720.64\;mGy{\cdot}cm$ on average (p < 0.05). 6. When the contrast medium was not used, the highest scanner was <8-slice MDCT> and its average was $612.07\;mGy{\cdot}cm$ in exposure dose in liver inspection(p < 0.05). when the contrast medium was used, the highest scanner was <8-slice MDCT scanner> and its average was $2,197.93\;mGy{\cdot}cm$ in exposure dose(p < 0.1). seventy six point two percent of medical facilities were in risk of radiation exposure while the number of phase was three to four times in their dose inspection of contrast medium.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.93-100
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• 2021

The purpose of this study is to find out the factors that affect the patient's exposure dose during the abdominal CT scan using the bolus tracking technique, and reducing the radiation exposure to the patient during the abdominal CT scan using the bolus tracking technique by adjusting the delay time according to the corresponding factor. The experiment was divided into two parts, and the first experiment was conducted with 300 patients There were 188 males and 112 females, and their average age was 58±12.18(19~85). In the second experiment, 150 subjects (100 males and 50 females) who were undergoing their follow-up examination among the first experiment subjects, and the difference in dose before and after was compared by applying the delay time according to the influencing factor. As a result of the first experiment, there was a relationship between the arrival time of the contrast media and the heart rate, and it was found that the arrival time decreased as the heart rate increased for both men and women. As a result of the second experiment, the average dose of CTDIvol and DLP before/after applying the delay time according to the heart rate decreased 4.98 mGy and 5.33 mGy·cm in the male group, and 3.54 mGy and 3.88 mGy·cm in the female group. By applying proper delay time according to the patient's heart rate during abdominal CT scan with the bolus tracking technique, the radiation exposure dose of the patient can be reduced.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.703-706
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• 2004

나선형 CT 혈관촬영에서 획득한 영상의 분석를 통해서 폐색전증이 의심되는 부위를 자동으로 검출하는 방법으로, 연구 대상은 20명의 환자를 대상으로 분석하였으며 CT 검사 후 방사선과 의사가 정상소견을 받은 환자 5명과 폐색전증이 있는 판독소견을 가진 15명을 대상으로 비교 분석하였다. CT 검사하는 동안에 조영제를 투입하면, 폐색전증이 발생한 부위는 조영제 양과 분포가 불균등하여 명암값이 낮게 검출된다. 검출방법으로는 전처리 작업으로 폐영역만을 분할하고, 분할된 폐영역에서 혈관을 찾기 위해 모폴로지기법를 적용하여 세선화(thinning) 작업을 진행한다. 다음 공정으로는 경계선을 찾아 local watershed를 적용하여 혈관을 검출하고, 검출된 혈관내에서 원형모델을 적용하여 모폴로지(morphology)을 통해 국소 부위의 미세한 농도변화를 인지하여 색전이 발생한 영역을 자동검출하였다. 본 논문의 자동검출시스템에서는 색전증이 있는 경우에 true positive의 발생빈도는 case 당 4.5개가 검출되었다. 정상인의 경우에도 혈류의 흐름, 혈류의 분기점, 노이즈로 인한 false positive의 빈도는 case 당 2.6개가 발생하여 전체적으로 false positive는 5.2개가 검출되었다. 본 논문은 false positive의 비율이 높게 검출되었지만 폐영역 CT 검사의 컴퓨터지원진단시스템(computer aided diagnosis)의 향후 연구과제에 방향을 제시할 수 있을 것이라 사료된다.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.137-142
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• 2016

When injecting intravenously of CT inspection, the effusion of the contrast meium can induce the tissue damage with the blood vessel outside. We detect extravasation which is generated in the course where we inject the contrast medium into the blood vessel. And we use the bolus tracking system for the detection of that. By using MPR and VR images, moreover we detected the extravasation in order to prevent the tissue damage. In order to detect the effusion of the contrast medium, we used 16-MDCT and 64-MDCT. Three dimensional images about the outflow of the blood vessel can provide the treatment information which is important in the patient treatment. Moreover we applied the image processing technique in order to improve sharpness between contrast media and organization. And sharpness and contrast was improved.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.173-174
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• 2015

간에서 발생하는 악성종양과 양성종양의 대표적 질환 으로는 간세포암(Hepatocelluar carci- noma, HCC)과 간혈관종(Hepatic hemangioma, HH)이다. CT검사를 이용한 진단에 있어서 두 질환은 시간변화에 따른 조영증강양상 차이가 나타난다. Liver 3-phase computed tomography검사를 시행하여 시간별 조영증강 양상을 알아보았다. 본 연구는 조영제 주입전, 동맥기(35sec), 문맥기(70sec), 지연기(180sec)에 대한 Enhan -cement Pattern 변화와 HU(Hounsfield unit)값 변화, pixel값 변화의 관찰로서 검증하였다. 실험결과 HU를 사용한 방법에서 의미있게 구분되었고 임상적용 시 판독에 도움을 줄 것으로 생각한다.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.244-252
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• 2011

This study was to estimate the radiation dose associated with 64-slice multidetector CT(MDCT) in clinical practice and quantify the potential cancer risk associated with these examinations. Lifetime attributable risks(LAR) were estimated with models developed in the national Academies' Biological Effects of Ionizing Radiation VII report. Mean effective dose were 1.48mSv in Brain axial scan, 7.66mSv in chest routine contrast, 12.17mSv in coronary angiogram, 24.52mSv in Dynamic abdomen scan. LAR estimates for brain routine varied from 1 in 7463 for man to 1 in 4926 for women. In chest routine with contrast, LAR varied from 1 in 1449 for men to 1 in 952. LAR of Abdomen dynamic CT varied from 1 in 453 for men to 1 in 298 for women. So, 64-slice MDCT scan is associated with non-negligible LAR of cancer. Doses can be reduced by careful attention to scanning protocol.