• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.19-25
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• 2009

Purpose: The aims of this study were to analyze correlation between the maximum standardized uptake value (SUVmax) of 2-[F-18]-fluoro-2-deoxy-d-glucose (FDG) on positron emission computed tomography (PET-CT) scan and the degree of contrast enhancement on computed tomography (CT) scan in lung cancers, and to recognize the difference in SUVmax and CT enhancement between groups of different histopathologic subtypes. Materials and Methods: Our study included 53 patients of pathologically confirmed primary lung cancer, who were performed PET-CT and post-contrast chest CT. We calculated initial and delayed SUVmax (SUV1, SUV2), difference between SUV1 and SUV2 (SUVd), retention index (RI), and the degrees of CT contrast enhancement of lung cancers. We analyzed these variables for subtypes of lung cancers. Results: The values (mean$\pm$ standard deviation) were $8.3{\pm}4.4$ for SUV1, $10.7{\pm}5.7$ for SUV2, $2.4{\pm}1.6$ for SUVd, $30{\pm}14$ for RI and $47.1{\pm}14.8$ HU (Hounsfield Unit) for degree of CT contrast enhancement. The difference of SUV1 and degree of CT enhancement between subtypes was not meaningful. SUV1 showed positive correlations with SUVd (r=0.74, p<0,01) and tumor size (r=0.58, p<0.01), but no significant correlation with degree of CT enhancement (r=0.06, p=0.69). In 10 cases, there was discrepancy in the same mass between the area of highest FDG-uptake and the area of highest contrast enhancement. Conclusion: We suggest that FDG uptake in lung cancer does not have a positive linear correlation with degree of CT enhancement. And there is no significant difference in FDG uptake and degree of CT enhancement between different subtypes of lung cancers.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.290-297
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• 2000

Background : Current non-invasive methods for evaluating the mediastinum by computed tomographic (CT) scan have limited sensitivity and specificity. The recently introduced PET was reported to be a more sensitive and specific method for the mediastinal staging of NSCLC (sensitivity : 76-100 %, specificity : 81-100%) than CT or MRI. We assessed the usefulness of PET in the mediastinal staging of NSCLC. Methods : We reviewed the medical records of NSCLC patients that had undertaken staging work-up by both CT and PET before thoracotomy between January 1997 and December 1998. A total of 23 patients were enrolled in the study (14 males and 7 females) with a mean age of 61$\pm$9 years. By comparing the clinical(CT and PET) and pathologic stagings, we evaluated the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET in thoracic nodal staging. Results : Sensitivity, specificity, positive predicted value and negative predicted value were 38%, 40%, 25% and 50% respectively for computed tomography, and 50%, 60%, 30% and 69% for PET. The accuracy of FDG-PET in our study was lower than that reported by previous other studies. Conclusion : The addition of FDG-PET to CT scanning has limited benefit for the thoracic nodal staging of NSCLC, but its value in our study was lower than that observed by others.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.776-780
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• 1998

Background: In patients with coronary artery disease, dysfunctional hypoperfused myocardium at rest may represent either nonviable or viable hibernating myocardium. Two-dimensional echocardiography can detect regional wall motion abnormalities resulting from myocardial ischemia by dobutamine infusion. The purpose of the present study was to identify the prediction of improvement of regional left ventricular(LV) function after surgical revascularization. Materials and methods: Sixteen patients with chronic regional LV dysfunction underwent dobutamine stress echocardiography(DSE) (dobutamine: baseline, 5, 10, 20$\mu$g/kg/min) before coronary artery bypass grafting(CABG) and underwent echocardiography at least 2 months after CABG. Results: All patients were male with mean age of 58 years ranging from 42 to 73 years. The mean LV ejection fraction was 41.8% with a range from 19% to 55%. During DSE, there were no complications, also, there were no operative morbidities or mortalities. Improvement of wall motion within the dysfunctional myocardium was found in 8(50%) of 16 patients in DSE. Among them, 6 patients(75%) showed functional recovery after CABG. Another 8 patients did not show improvement of wall motion in DSE. But among them, 3 patients(38%) showed functional recovery after CABG. 84 dysfunctional segments were found in 256 segments of 16 patients. Improvement of wall motion was found in 34 of 84 segments in DSE. Among them, 23 segments(74%) showed functional recovery after CABG. Another 53 segments did not show improvement of wall motion in DSE. But among them, 12 segments(23%) showed functional recovery after CABG. The sensitivity and specificity of DSE for the prediction of postoperative improvement of segmental wall motion were 66% and 84%, respectively. The positive and negative predictive value of DSE were 74% and 77%, respectively. In patients with chronic regional LV dysfunction, think that DSE is a good predictor of the improvement of dysfunctional segments after CABG.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.180-189
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• 2004

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.

• Tuberculosis and Respiratory Diseases
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• v.53 no.1
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• pp.46-51
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• 2002

Numb chin syndrome is a rare clinical manifestation, characterized by focal sensory loss and paresthesia of the chin. It is more often associated with cancer than with benign disorders, and can be the first manifestation of a cancer. A 60-year-old man presented with focal numbness of right chin and gingiva for 10 days. Chest computed tomograghy showed a 3 cm sized mass on the distal left main- stem bronchus. Squamous cell carcinoma was diagnosed on bronchoscopic biopsy. However, bony metastasis of mandible was not evident on reontgenogram, CT scan, bone scintigram and positron emission tomography. Despite the chemotherapy with three cycles of paclitaxel and cisplatinum, the cancer was progressed and pain on the right chin was developed 4 months later. Bone scintigram showed multiple bony metastasis including mandible. Here we report this case with a brief review of the appropriate literature.

• 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.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.188-197
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• 2015

Purpose: To investigate the patterns of care for patients with nasopharyngeal carcinoma (NPC) in South Korea. Materials and Methods: A multi-institutional retrospective study was performed (Korean Radiation Oncology Group [KROG] 11-06) on a total of 1,445 patients from 15 institutions. Results: Of the 1,445 patients, more than half were stages III (39.9%) and IV (35.8%). In addition to patterns of care, we also investigated trends over time with the periods 1988-1993, 1994-2002, and 2003-2011. The frequencies of magnetic resonance imaging and positron emission tomography-computed tomography were markedly increased in the third period compared to previous 2 periods. Concurrent chemoradiation (CCRT) was performed on 894 patients (61.9%), neoadjuvant chemotherapy on 468 patients (32.4%), and adjuvant chemotherapy on 366 patients (25.3%). Of stage II-IV patients, CCRT performed on 78.8% in 2003-2011 compared to 15.0% in 1988-1993. For patients treated with CCRT, cisplatin was the most commonly used agent in 81.3% of patients. Over the periods of time, commonly used radiotherapy (RT) techniques were changed from 2-dimensional RT (1988-1993, 92.5%) to 3-dimensional RT (2003-2011, 35.5%) or intensity-modulated RT (IMRT; 2003-2011, 56.5%). Median RT doses given to primary tumors, high-risk lymphatics, and low-risk lymphatics were 70.0 Gy, 58.1 Gy, and 48.0 Gy, respectively. Adoption of IMRT increased the dose per fraction and escalated total radiation dose. Conclusion: Assessment of the patterns of care for NPC patients in South Korea demonstrated that management for NPC including diagnostic imaging, treatment regimen, RT techniques and dose schedule, advanced in accordance with the international guidelines.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.201-208
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• 2008

Purpose: We aimed to assess the role of positron emission tomography using fluorodeoxyglucose (FDG-PET) in the diagnosis of recurrence or the assessment of therapeutic response in cervical and ovarian cancer patients through making a comparison between FDG-PET, abdominal computed tomography (CT) and serum tumor marker. Materials and methods: We included 103 cases (67 patients) performed FDG-PET and abdominal CT. There were 42 cervical cancers and 61 ovarian cancers. We retrospectively reviewed the interpretations of PET and CT images as well as the level of tumor marker. We calculated their sensitivity, specificity, positive predictive value and negative predictive value for these three modalities. And then we analyzed the differences between these three modalities. Results: Tumor recurrences were diagnosed in 37 cases (11 cervical cancers and 26 ovarian cancers). For PET, CT and tumor marker, in cervical cancer group, sensitivity was 100% (11/11), 54.5% (6/11) and 81.1% (9/11), respectively. And specificity was 93.6% (29/31), 93.6% (29/31) and 100% (31/31). In ovarian cancer group, sensitivity was 96.2% (25/26), 84.6% (22/26) and 80.8% (21/26), and specificity was 94.3% (33/35), 94.3% (33/35), 94.3% (33/35), PET was highly sensitive to detect the intraperitoneal and extraperitoneal metastasis with the help of the CT images to localize the lesions. However, CT had limitations in differentiation of the recurrent tumor from benign fibrotic tissue, identification of viable tumors at the interface of tissues, and detecting extraperitoneal lesions. Conclusion: FDG-PET can be an essential modality to detect the recurrent or residual tumors in gynecologic cancer patients because of its great field of the application and high sensitivity.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.9-13
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• 2016

Purpose PET-CT examinations using $^{18}F-FDG$ to treat urinary system cancer are limited in terms of anatomical structure and excretion route of $^{18}F-FDG$. But one of the ongoing examinations utilizing $^{11}C-Acetate$ can compensate for such defects. We would like to introduce a clinical application of $^{11}C-Acetate$ PET-CT in urinary cancer patients. Materials and Methods We conducted a clinical survey of 22 patients diagnosed with urinary cancer at our hospital, 10 prostate cancer patients, 10 renal cell carcinoma patients, and 2 bladder cancer patients. All patients were performed $^{18}F-FDG$ PET-CT examinations, $^{11}C-Acetate$ examinations were performed after two weeks on average. The equipment used to D-710 PET-CT in GE Company and we performed PET-CT procedures 15 minutes after injecting $^{11}C-Acetate$, and a medical doctor from the department of nuclear medicine appraised and compared images between $^{18}F-FDG$ and $^{11}C-Acetate$. Results According to our survey, prostate cancer patients generally had lower uptake of $^{18}F-FDG$ than other cancer patients did. In 2 out of 10 prostate cancer patients, metastasized cancer showed greater uptake in $^{11}C-Acetate$ than $^{18}F-FDG$. In renal cell carcinoma cases, 8 out of 10 patients displayed evidently greater uptake in $^{11}C-Acetate$ than $^{18}F-FDG$. We excluded bladder cancer cases in this study because uptake of $^{18}F-FDG$ in the bladder was too hot, the number of patients was insufficient, and the cases did not meet criteria such as the use of diuretics. Conclusion It is too premature to draw solid conclusions from the survey, since it involved only a small number of participants. However, there are a number of studies conducted abroad that prove the effectiveness of the $^{11}C-Acetate$ PET-CT examinations in treating urinary system cancer, and this study is still ongoing at our hospital. If the tests were to be conducted on a larger number of participants, this study could lead to numerous other potential research topics, such as the correlation between Prostatic specific antigen (PSA) values and $^{11}C-Acetate$ PET-CT, Gleason sum values from biopsy before surgery, Specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV) between $^{18}F-FDG$ PET-CT examinations and $^{11}C-Acetate$ PET-CT examinations in other urinary system cancers.

• 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.