• 핵의학기술
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• 제16권2호
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• pp.57-61
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• 2012

전신 뼈 검사에 이용되는 방사성의약품의 주된 집적부위는 뼈 무기질이며 그 섭취기전은 명백히 밝혀져 있지 않다. 전신 뼈 검사에서 일시적으로 미만성 간 섭취가 나타날 수 있으며, 간내 섭취의 원인은 다양하게 보고되고 있다. 본 연구에서는 전신 뼈 검사에서 $^{99m}Tc$-DPD의 미만성 간 섭취에 MRI 조영제가 미치는 영향을 알아보았다. 2010년 1월부터 12월 사이에 $^{99m}Tc$-DPD 전신 뼈 검사를 시행한 환자 중 982명을 연구의 대상으로 하였다. 982명의 환자는 전신 뼈 검사 이전에 MRI 조영제를 사용한 검사를 시행하였다. 혈액학검사 및 일반화학검사 소견을 조사한 결과 전신 뼈 검사에서 46명의 환자(남:여=39:7)가 미만성 간 섭취를 보였다. 추적 전신 뼈 검사를 시행하였으며, 이전에 보였던 미만성 간 섭취는 모두 소실되어 정상적인 소견을 보였다. 간기능 및 신기능 검사는 모두 정상이었다. 전신 뼈 검사에서 $^{99m}Tc$-DPD의 미만성 간 섭취에 MRI 조영제가 간접적인 영향을 주고 있다. $^{99m}Tc$-DPD의 미만성 간 섭취를 피하기 위해서 전신 뼈 검사는 MRI 조영제를 사용한 검사를 시행하기에 앞서서 먼저 시행하여야 하고, MRI 조영제를 사용한 검사가 있을 경우에는 조영제가 몸에서 제거된 후 검사를 시행하여야 할 것이다.

• 대한핵의학회지
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• 제36권3호
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• pp.203-208
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• 2002

만성간질환 환자에서 호흡곤란을 초래하는 간폐 증후군 발생한다는 사실은 잘 알려져 있다. 단락을 입증하기 위해서는 대비증강심초음파, 폐혈관조영술, $^{99m}Tc-MAA$ 폐관류스캔 등을 이용할 수 있다. 이 중에서도 $^{99m}Tc-MAA$를 이용한 폐관류스캔은 매우 안전하고 간편하게 단락의 존재 여부를 확인할 수 있으며, 단락의 양을 계산할 수도 있다. 정량이 가능하므로 병의 경과를 추적하는 지표로서도 유용할 것이다. 저자들은 $^{99m}Tc-MAA$ 폐관류스캔으로 진단한 간폐증후군의 증례를 문헌고찰과 함께 보고하였다.

• Nuclear Medicine and Molecular Imaging
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• 제40권1호
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• pp.48-50
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• 2006

A 38-year-old female with arthralgia in right elbow joint for 6 months was referred for a bone scan which showed diffuse uptakes of $^{99m}Tc$-MDP in the liver and spleen without hepatosplenomegaly. She had a history of hepatitis B vaccination 3 days ago. These uptakes were disappeared on the follow-up bone scan after 4 months. We suggest this transient diffuse hepatic uptake after vaccination of hepatitis B might be due to aluminum component within the hepatitis B vaccine as adjuvant.

• Journal of Gastric Cancer
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• 제11권4호
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• pp.234-238
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• 2011

A 67 year old male at a regular checkup underwent esophagogastroduodenoscopy. On performing esophagogastroduodenoscopy, a lesion about 1.2 cm depressed was noted at the gastric angle. The pathology of the biopsy specimen revealed a well-differentiated adenocarcinoma. On performing an abdominal computed tomography (CT) scan & positron emission tomography-computed tomography (PET-CT) scan, no definite evidence of gastric wall thickening or mass lesion was found. However, lymph node enlargement was found in the left gastric and prepancreatic spaces. This patient underwent laparoscopic assisted distal gastrectomy and D2 lymph node dissection. On final examination, it was found out that the tumor had invaded the mucosal layer. The lymph node was a metastasized large cell neuroendocrine carcinoma with an unknown primary site. The patient refused chemotherapy. He opted to undergo a close followup. At the postoperative month 27, he had a focal hypermetabolic lesion in the left lobe of the liver that suggested metastasis on PET-CT scan. He refused to undergo an operation. He underwent a radiofrequency ablation.

• 인터넷정보학회논문지
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• 제21권3호
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• pp.103-111
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• 2020

Liver cancer is the most fatal cancer that occurs worldwide. In order to diagnose liver cancer, the patient's physical condition was checked by using a CT technique using radiation. Segmentation was needed to diagnose the liver on the patient's abdominal CT scan, which the radiologists had to do manually, which caused tremendous time and human mistakes. In order to automate, researchers attempted segmentation using image segmentation algorithms in computer vision field, but it was still time-consuming because of the interactive based and the setting value. To reduce time and to get more accurate segmentation, researchers have begun to attempt to segment the liver in CT images using CNNs, which show significant performance in various computer vision fields. The pixel value, or numerical value, of the CT image is called the Hounsfield Unit (HU) value, which is a relative representation of the transmittance of radiation, and usually ranges from about -2000 to 2000. In general, deep learning researchers reduce or limit this range and use it for training to remove noise and focus on the target organ. Here, we observed that the range of HU values was limited in many studies but different in various liver segmentation studies, and assumed that performance could vary depending on the HU range. In this paper, we propose the possibility of considering HU value range as a hyper parameter. U-Net and ResUNet were used to compare and experiment with different HU range limit preprocessing of CHAOS dataset under limited conditions. As a result, it was confirmed that the results are different depending on the HU range. This proves that the range limiting the HU value itself can be a hyper parameter, which means that there are HU ranges that can provide optimal performance for various models.

• Journal of Yeungnam Medical Science
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• 제3권1호
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• pp.163-169
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• 1986

Intrapulmonary shunt was measured by $^{99m}Tc$-MAA perfusion tung scan. The study was included 76 patients. Significant amount of intrapulmonary shunt was observed in the pulmonary disease patients and liver disease patients. The shunt amount was correlated well with $PaO_2$ and $AaDO_2$ level. Further study is needed to search the various factors affecting the amount of intrapulmonary shunt.

• Journal of Chest Surgery
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• 제33권3호
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• pp.257-261
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• 2000

Pulmonary arteriovenous fistula can occur in a variety of clinical situations including liver diseases, infections, metastatic carcinomas, systemic disorders, and after the palliation of congenital heart diseases. A 72-day-old male infant with Tetralogy of Fallot and pulmonary atresia underwent surgical correction without difficulty. However, ventilator weaning in the ICU failed initially because of an unexplained postoperative hypoxemia(FiO2: 0.8, PaO2: 40 mmHg, SaO2: 80∼90%). Postoperative follow-up lung perfusin scan at postoperative 15 days showed right-to-left shunt(33.6%) and ventilator weaning was performed on the 20th day after the operation (FiO2: 0.4, PaO2, 50mmHg, SaO2: 86.9%). Arterial oxygen saturation under room air was 80∼85% at 7 months postoperatively. One and half year follow-up lung perfusion scan showed decreased amount of right-to-left shunt (11.2%). We report a case with a review of the literatures.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.366-369
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• 1997

In this study, we measured upper right, lower right, upper left region to find the optimal region which represent liver function. We found that the upper right region is optimal because of high accuracy and low standard deviation. For normal subjects all the calculated HEFs were greater than 100% and all those of abnormal ones were less than 80%. Thus HEF can be assumed to discriminate abnormal livers from normal ones. It was found that the patients with surgical operation would survive if both the pre-and the post-operative HEFs are greater than 50%. Therefore HEF method can be a good estimator for surgeon to determine the surgical operation and to evaluate remaining hepatic function after surgery as well as it is reliable and simple.

• 한국콘텐츠학회논문지
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• 제17권11호
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• pp.50-59
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• 2017

최근 임상에서 활용하고 있는 일체형 PET-MRI의 간암 진단능력을 평가하기 위해 $2{\times}2$ 판정행렬을 이용하여 유용성을 평가하였다. 실험대상의 PET-MRI 검사 결과를 통해 간암 판정 여부 즉 비정상과 정상 판정을 받은 경우는 각각 98건, 51건 이었으며, 세포병리학적 결과가 양성과 음성 판정을 받은 경우는 각각 103건, 62건으로 나타났다. 이 중 두가지 검사에서 진양성의 경우는 95건, 위양성은 3건으로 나타났으며, 진음성은 62건, 위음성의 경우는 5건으로 분석되었다. 실험결과 PET-MRI 검사의 예민도는 95.00%, 특이도는 95.38%, 위음성률은 0.05%, 위양성률은 0.05%, 정확도는 95.15%로 분석되었다. 따라서 간암의 진단에 있어 수술 전 병기 결정이나 치료 후 재발 및 원격전이의 발견, 불분명한 원발 림프절 전이 등의 평가 등에 활용 가능성이 높을 것으로 판단되며, 특히 병리학적 검사와의 복합적 진단 및 추적검사를 통해 간암 진단을 위한 PET-MRI 임상적 유용성은 충분할 것으로 사료된다.

• 대한핵의학회지
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• 제23권2호
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• pp.219-223
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• 1989

Inflammation scan using radiolabelled leukocytes has high sensitivity and specificity. Several methods for labelling leukocytes have been evaluated using P-32 diisopropyl fluorophosphate (DFP-32), H-3 thymidine, Cr-51 chromate, Ga-67 citrate and Tc-99m-sulfur colloid. In-111-oxine has proved so far to be the most reliable agent for labelling leukocytes. In-111-oxine is, however, expensive, not easily available when needed, and its radiation dose to leukocytes is relatively high. Moreover, resolution of the resultant image is relatively poor. Tc-99m is still the agent of choice because of, as compared with the indium, its favorable physical characteristics, lower cost and availability. Now the technique for labelling the leukocytes with technetium is successfully obtained using the lipophilic HAPAO with higher efficiency for granulocytes than for other cells. With this technique it is possible to label leukocytes in plasma to improve the viability of the leukocytes. Inflammation scan using Tc-99m-HMPAO has been evaluated in several laboratories, and difference in methods for separation and labelling accounts for difference in efficiency, viability and biodistribution of the labelled leukocytes. We performed inflammation scan using leukocytes labelled with Tc-99m-HMPAO in three dogs 24 hours after inoculation of live E. Coli and A. Aureus in their right abdominal wall. We separated mixed leukocytes by simple sedimentation using 6% hetastarch (HES) and labelled the leukocytes with Tc-99m-HMPAO in 20% cell free plama diluted with phosphate buffer solution(Fig. 1). Uptake was high in the liver and spleen but is was minimal in the lungs on whole body scan. Kidneys and intestine showed minimal activity although it was high in the urinary bladder(Fig. 2). Uptake of labelled leukocytes in the inflammation site was do(mite on 2 hour-postinjection scan and abscess was clearly delineated on 24 hour-delayed scan with high target-to-nontarget ratio(Fig. 3, 4). Inflammation scan using mixed leukocytes labelled with Tc-99m-HMPAO is very sensitive and specific in early detection of inflammation.