• Title/Summary/Keyword: positron

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Diagnosis of Primary Malignant Lesion Using $^{18}F$ FDG PET/CT in Metastatic Bone Tumor (전이성 골종양에서 $^{18}F$ FDG PET/CT를 이용한 원발성 악성 질환의 진단)

  • Yoon, Hoi-Soo
    • The Journal of the Korean bone and joint tumor society
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    • v.14 no.1
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    • pp.44-50
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    • 2008
  • Purpose: To evaluate usefulness in diagnosing primary malignant lesion of metastatic bone tumor using $^{18}F$ FDG PET/CT. Material & Methods: Retrospective analysis was executed on 5,452 patients who were taken with $^{18}F$ FDG PET/CT between December 2003 and December 2007. 180 patients who had not any history of malignancy and complained musculoskeletal pain and had ill-defined osteolytic lesion in plain X-ray, were included. 96 male and 84 female were enrolled and mean age was 59.1 year old (22~90). We analyzed diagnostic accuracy, age and sex distribution of primary malignant lesion, location of metastatic lesion. Results: We could confirmed primary malignant lesion in 152 cases (84.4%). Most common malignant primary lesion was lung (28.3%), breast (18.9%) and gastrointestinal system (16.7%) and spine was the most common metastatic location of primary malignant lesion. Conclusion: $^{18}F$ FDG PET/CT is a effective molecular imaging detecting primary malignant lesion in patients having metastatic bone lesion without history of malignancy.

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A Study on Electrolysis of Heavy Water and Interaction of Hydrogen with Lattice Defects in Palladium Electrodes (팔라디움전극에서 중수소의 전기분해와 수소와 격자결함의 반응에 관한 연구)

  • Ko, Won-Il;Yoon, Young-Ku;Park, Yong-Ki
    • Nuclear Engineering and Technology
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    • v.24 no.2
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    • pp.141-153
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    • 1992
  • Excess tritium analysis was peformed to verify whether or not cold fusion occurs during electrolysis of heavy water in the current density range of 83~600 mA/$\textrm{cm}^2$ for a period of 24 ~ 48 hours with use of palladium electrodes of seven different processing treatments and geometries. The extent of recombination of D$_2$ and $O_2$gases in the electrolytic cell was measured for the calculation of accurate enthaplpy values. The behavior and interaction of hydrogen atoms with defects in Pd electrodes were examined using the Sieverts gas charging and the positron annihilation(PA) method. Slight enrichment of tritium observed was attributed to electrolytic enrichment but not to the formation of a by-product of cold fusion. The extent of recombination of D$_2$and $O_2$gases was 32%. Hence the excess heat measured during the electrolysis was considered to be due to the exothermic reaction of recombination but not to nuclear fusion. Lifetime results from the PA measurements on the Pd electrodes indicated that hydrogen atoms could be trapped at dislocations and vacancies in the electrodes and that dislocations were slightly more preferred sites than vacancies. It was also inferred from R parameters that the formation of hydrides was accompanied by generation of mostly dislocations. Doppler broadening results of the Pd electrodes indicated that lattiec defect sites where positrons were trapped first increased and then decreased, and this cycle was repeated as electrolysis continued. It can be inferred from PA measurements on the cold-rolled Pd and the isochronally annealed Pd hydride specimens that microvoid-type defects existed in the hydrogen-charged electrode specimen.

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Multi-modality MEdical Image Registration based on Moment Information and Surface Distance (모멘트 정보와 표면거리 기반 다중 모달리티 의료영상 정합)

  • 최유주;김민정;박지영;윤현주;정명진;홍승봉;김명희
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.3_4
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    • pp.224-238
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    • 2004
  • Multi-modality image registration is a widely used image processing technique to obtain composite information from two different kinds of image sources. This study proposes an image registration method based on moment information and surface distance, which improves the previous surface-based registration method. The proposed method ensures stable registration results with low registration error without being subject to the initial position and direction of the object. In the preprocessing step, the surface points of the object are extracted, and then moment information is computed based on the surface points. Moment information is matched prior to fine registration based on the surface distance, in order to ensure stable registration results even when the initial positions and directions of the objects are very different. Moreover, surface comer sampling algorithm has been used in extracting representative surface points of the image to overcome the limits of the existed random sampling or systematic sampling methods. The proposed method has been applied to brain MRI(Magnetic Resonance Imaging) and PET(Positron Emission Tomography), and its accuracy and stability were verified through registration error ratio and visual inspection of the 2D/3D registration result images.

Ictal single-photon emission computed tomography with slow dye injection for determining primary epileptic foci in infantile spasms (영아연축에서 추적자의 느린 점적주사를 이용한 발작기 SPECT)

  • Hur, Yun Jung;Lee, Joon Soo;Kang, Hoon Chul;Park, Hye Jung;Yun, Mi Jin;Kim, Heung Dong
    • Clinical and Experimental Pediatrics
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    • v.52 no.7
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    • pp.804-810
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    • 2009
  • Purpose : We investigated whether ictal single-photon emission computed tomography (SPECT) with prolonged injection of technetium-99m (99mTc) ethyl cysteinate dimer during repeated spasms can localize the epileptogenic foci in children with infantile spasms. Methods : Fourteen children with infantile spasms (11 boys, 3 girls; mean age, $2.2{\pm}1.3$ years) were examined. When a cluster of spasms was detected during video electroencephalography (EEG) monitoring, $^{99m}Tc$ ethyl cysteinate dimer was slowly and continuously injected for 2 minutes to determine the presence of ictal SPECT. For 7 children, the ictal and interictal SPECT images were visually analyzed, while for the remaining 7 children, the SPECT images were analyzed using the subtraction ictal SPECT coregistered to magnetic resonance imaging (MRI) (SISCOM) technique. Subsequently, we analyzed the association between the ictal SPECT findings and those of other diagnostic modalities such as EEG, MRI, and positron emission tomography (PET). Results : Increase in cerebral blood flow on ictal SPECT involved the epileptogenic foci in 10 cases6 cases analyzed by visual assessment and 4 analyzed by the SISCOM technique. The ictal SPECT and video-EEG findings showed moderate agreement (Kappa=0.57; 95% confidence interval, 0.18-0.96). Conclusion : Ictal SPECT with prolonged injection of a tracer could provide supplementary information to localize the epileptogenic foci in infantile spasms.

Protective Effect of Soybean-Derived Phosphatidylserine on the Trimethyltin-Induced Learning and Memory Deficits in Rats

  • An, Yong Ho;Park, Hyun Jung;Shim, Hyun Soo;Choe, Yun Seok;Han, Jeong Jun;Kim, Jin Su;Lee, Hye Jung;Shim, Insop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.3
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    • pp.337-345
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    • 2014
  • The present study examined the effects of soybean-derived phosphatidylserine (SB-PS) on the learning and memory function and the neural activity in rats with trimethyltin (TMT)-induced memory deficits. The cognitive improving efficacy of SB-PS on the amnesic rats, which was induced by TMT, was investigated by assessing the Morris water maze test and by performing cholineacetyl transferase (ChAT), acetylcholinesterase (AChE) and cAMP responsive element binding protein (CREB) immunohistochemistry. A positron emission tomography (PET) scanning the rat brain was by performed administer 18F-Fluorodeoxy-glucose (18F-FDG). The rats with TMT injection showed impaired learning and memory of the tasks and treatment with SB-PS produced a significant improvement of the escape latency to find the platform in the Morris water maze at the 2nd day compared to that of the MCT group. In the retention test, the SB-PS group showed increased time spent around the platform compared to that of the MCT group. Consistent with the behavioral data, SB-PS 50 group significantly alleviated the loss of acetyl cholinergic neurons in the hippocampus compared to that of the MCT group. Treatment with SB-PS significantly increased the CREB positive neurons in the hippocampus as compared to that of the MCT group. In addition, SB-PS groups increased the glucose uptake in the hippocampus and SB-PS 50 group increased the glucose uptake in the frontal lobe, as compared to that of the MCT group. These results suggest that SB-PS may be useful for improving the cognitive function via regulation of cholinergic marker enzyme activity and neural activity.

Utility of FDG PET-CT Scans on Nodal Staging of Squamous Cell Carcinoma in the Oral Cavity and Oropharynx (구강 및 구인두 편평상피암종의 림프절 전이에 대한 PET-CT 영상의 유용성)

  • Joo, Young-Hoon;Sun, Dong-Il;Park, Jun-Ook;Yoo, Ie-Ryung;Kim, Min-Sik
    • Korean Journal of Head & Neck Oncology
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    • v.26 no.1
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    • pp.14-18
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    • 2010
  • Objectives : We evaluated the use of FDG PET/CT for the identification of cervical nodal metastases of SCC of the oral cavity and oropharynx with histological correlation. Material and Methods : We reviewed 46 medical records, from January 2004 to July 2007, of patients who underwent FDG PET/CT and CT/MRI for SCC of the oral cavity and oropharynx before surgery. We recorded the lymph node metastases according to the neck level affected and the system used for the imaging-based nodal classification. Results : The FDG PET/CT had a sensitivity of 75.6% and a specificity of 96.7% ; it had a higher sensitivity than the CT/MRI for identification of cervical metastases on the side of the neck(26/28 vs. 20/28, p=0.031) and at each of the cervical levels(34/45 vs. 26/45, p=0.008). There was a significant difference in the $SUV_{max}$ between the benign and malignant cervical lymph nodes($3.31{\pm}3.23$ vs. $4.22{\pm}2.57$, p=0.028). The receiver-operating-characteristic (ROC) curve analysis for differentiating the benign from the malignant cervical lymph nodes, showed that the area under the curve(AUC) of the FDG PET/CT was 0.775. The cut-off value for the $SUV_{max}$ was 2.23 based on the ROC curve. There was a significant correlation between the $SUV_{max}$ and the size of the cervical lymph nodes(Spearman r=0.353, p=0.048). Conclusion : FDG PET/CT images were more accurate than the CT/MRI images. In addition, the $SUV_{max}$ cut-off values were important for evaluating cervical the cervical nodes in the patients with SCC of the oral cavity and oropharynx.

Burnt-out Metastatic Prostate Cancer

  • Shin, Dong Suk;Koo, Dong Hoe;Yoo, Suhyeon;Ju, Deok Yun;Jang, Cheol Min;Joo, Kwan Joong;Shin, Hyun Chul;Chae, Seoung Wan
    • Journal of Yeungnam Medical Science
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    • v.30 no.2
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    • pp.116-119
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    • 2013
  • A burnt-out prostate cancer tumor is a very rare clinical entity. The term 'burnt-out' refers to a primary tumor that has spontaneously and nearly completely regressed without treatment. Since metastasis of prostate cancer is usually encountered in the presence of advanced disease, distant metastasis with an undetectable primary tumor is very rare. We report herein a case of a burnt-out prostate cancer tumor that metastasized to the thoracic (T) spine and caused cord compression. A 66-year-old man visited the Emergency Department due to weakness of both legs for the past two days. His blood and urine tests were normal at the time. His spine magnetic resonance imaging (MRI) scans looked like bone metastasis that involved the T-7 vertebral body and a posterior element, and caused spinal cord compression. Other images, including from the brain MRI, neck/chest/abdomino-pelvic computed tomography (CT) scan and 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) and endoscopy, revealed no lesions that suggested malignancy. After total corpectomy T-7 and screw fixation/fusion at T5 to T10, the pathology report revealed a metastatic carcinoma that was strongly positive for prostate-specific antigen (PSA). The serum PSA value was 1.5 ng/mL. The transrectal 12-core prostate biopsy and ultrasonography showed no definitive hypoechoic lesion, but one specimen had slight (only 1%) adenocarcinoma with a Gleason score of 6 (3+3). The final diagnosis was burned-out prostate cancer with an initial normal PSA value. Although metastatic disease with an unknown primary origin was confirmed, a more aggressive approach in seeking the primary origin could provide a more specific treatment strategy and greater clinical benefit to patients.

Pre-treatment Metabolic Tumor Volume and Total Lesion Glycolysis are Useful Prognostic Factors for Esophageal Squamous Cell Cancer Patients

  • Li, Yi-Min;Lin, Qin;Zhao, Long;Wang, Li-Chen;Sun, Long;Dai, Ming-Ming;Luo, Zuo-Ming;Zheng, Hua;Wu, Hua
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1369-1373
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    • 2014
  • Objectives: To study application of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) with $^{18}F$-FDG PET/CT for predicting prognosis of esophageal squamous cell cancer (ESC) patients. Methods: Eighty-six patients with ESC staged from I to IV were prospectively enrolled. Cisplatin-based chemoradiotherapy (CCRT) or palliative chemoradiotherapy were the main treatment methods and none received surgery. $^{18}F$-FDG PET/CT scans were performed before the treatment. SUVmax, MTV, and TLG were measured for the primary esophageal lesion and regional lymph nodes. Receiver operating characteristic curves (ROCs) were generated to calculate the P value of the predictive ability and the optimal threshold. Results: MTV and TLG proved to be good indexes in the prediction of outcome for the ESC patients. An MTV value of 15.6 ml and a TLG value of 183.5 were optimal threshold to predict the overall survival (OS). The areas under the curve (AUC) for MTV and TLG were 0.74 and 0.70, respectively. Kaplan-Meier analysis showed an MTV less than 15.6 ml and a TLG less than 183.5 to indicate good media survival time (p value <0.05). In the stage III-IV patient group, MTV could better predict the OS (P < 0.001), with a sensitivity and specificity of 0.80 and 0.67, respectively. Conclusions: Pre-treatment MTV and TLG are useful prognostic factors in nonsurgical ESC.

A Case of Extensive Stage Small Cell Lung Cancer Presenting as an Acute Appendicitis with Perforation (전이성 병소에 의해 발생한 급성 충수염의 천공으로 진단된 전신병기 소세포폐암 1예)

  • Shin, Dong Won;Choi, Moon Han;Park, Seung Sik;Park, Sung Woo;Kim, Ki Up;Jang, An Soo;Park, Choon-Sik;Lim, Cheol Wan;Ko, Eun Suk;Paik, Sang Hyun;Kim, Do Jin
    • Tuberculosis and Respiratory Diseases
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    • v.65 no.3
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    • pp.230-234
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    • 2008
  • The incidence of appendiceal metastatic cancer is quite low. In particular, in small cell lung cancer, there is a very low incidence of a metastasis to the appendix. A 75-years old man with right lower quadrant pain, cough and sputum was transferred to our hospital. Abdominal CT revealed acute appendicitis with a perforation. The patient underwent surgery. The frozen sections of the tissue obtained during surgery, indicated a malignancy, but a right hemicolectomy was not performed due to the patient's poor general condition. The histology findings of the appendix were identified as a small cell carcinoma. The abdominal CT scan and chest x-ray at admission day showed a mass in the right lower lobe, and a further evaluation of the lesion was performed including positron emission tomography and flexible bronchoscopy with a biopsy. The pathology findings of the lung mass were also small cell lung cancer. The specimens from both sites stained positive for cytokeratin, cluster designation 56, synaptophysin, chromogranin-A and thyroid transcription factor 1. It was concluded that the appendiceal small cell cancer originated from the lung.

Usefulness of a FDG-PET Scan in Assessing Recurrent Gastric Cancer (재발한 위암의 진단에 사용된 FDG-PET의 유용성)

  • Lee Hyeon Kook;Lee Kyu Eun;Kim Yoon Ho;Jeong Jae Min;Yang Han-Kwang;Chung June Key;Lee Kuhn Uk;Choe Kuk Jin
    • Journal of Gastric Cancer
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    • v.1 no.3
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    • pp.174-179
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    • 2001
  • Purpose: For curative resection of recurrent gastric cancer, it is imperative that there be no unrecognized foci of tumoral disease outside the operation field. PET (positron emission tomography) with FDG (18 fluoro-2 deoxy-D-glucose) is a whole-body imaging technique that exploits the increased rate of glycolysis in tumor cells to detect disease. The authors evaluated the usefulness of FDG-PET in assessing resectability of recurrent gastric cancer. Materials and Methods: Seven patients with recurrent gastric cancer were studied with FDG-PET from December 1998 to October 2000. All FDG-PET images were interpreted in conjunction with conventional diagnostic methods. All imaging results were correlated with the pathological diagnosis and clinical outcome. Results: A final diagnosis of recurrence was obtained at 14 sites in all 7 patients by histology or clinical follow up. Locoregional recurrence, including distant metastasis, developed in 6 of 7 patients and distant recurrence in only one. FDG-PET detected all recurrent sites (5 locoregional and 5 distant) in 5 patients without peritoneal recurrence, but did not detect peritoneal seeding in 2 patients with peritoneal recurrence. The accuracy of FDG-PET in estimating resectability was $71.4\%$ (5/7), and that of CT and PET together was $85.7\%$ (6/7). A curative resection could be performed in three of the recurrent patients (2 locoregional and 1 distant recurrence). Conclusion: Our results suggest that FDG-PET may be useful for detecting locoregional and distant recurrence of gastric cancer and for selecting appropriate treatment. However, considering that FDG-PET was limited in detecting peritoneal seeding and determining the exact anatomical extension of tumor, it should be used in conjunction with other anatomical images.

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