• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.2
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• pp.32-36
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• 2022

Purpose There are reports that the COVID-19 vaccine causes false positive uptake of axillary lymph nodes. Therefore, this paper intends to evaluate the change in SUVmax of axillary lymph nodes with the period after the COVID-19 vaccination. Materials and Methods In 134 breast cancer patients who were tested for ¹⁸F-FDG PET/CT at Severance hospital, 3.7 MBq/kg of ¹⁸F-FDG was intravenously injected and scanned for 2 minutes per bed after 60 minutes. The equipment was Discovery 600 (GE Healthcare, MI, USA). The period was divided into four groups, 0 to 2 weeks, 3 to 6 weeks, 7 to 10 weeks, and 11 weeks or more. SUVmax was measured after checking the uptake of axillary lymph nodes on the ipsilateral side of vaccination and the Kruskal-Wallis test was performed using SPSS Statistics 28 (IBM Corp., Armonk, NY, USA). Results From 0 to 2 weeks groups to 11 weeks or more group, the average of SUVmax was measured in the order of 5.52, 2.85, 1.82, and 1.7. As a result of the Kruskal-Wallis test, there was a significant difference between 0 to 2 weeks group from all other groups (P < 0.05), and there was no significant difference between the remaining three groups. Conclusion The SUVmax of axillary lymph nodes decreased over the period after the COVID-19 vaccination and no significant difference was found after 3 weeks of vaccination. Therefore, it is recommended to record COVID-19 vaccination information before examination.

• Korean Journal of Head & Neck Oncology
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• v.19 no.2
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• pp.142-147
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• 2003

Purpose: Accurate evaluation of metastatic cervical lymph nodes plays a decisive role in the treatment and prognosis of patients with squamous cell carcinoma of the head and neck. The purpose of this study is to investigate the usefulness of FDG-PET for diagnosis of cervical metastasis in the head and neck cancer by comparing with the conventional imaging study. Materials and Methods: The subjects on this study were 30 patients (24 males and 6 females, aged 39 to 76, mean 57.1) diagnosed as pathologic-proven squamous cell carcinomas of the head and neck. All patients underwent preoperative FDG-PET, CT(n=27) or MRI (n=3). Their medical records were reviewed retrospectively. Using pathologic reports as a golden standard, the results of FDG-PET were compared with conventional imaging study (CT/MRI) in the evaluation of cervical metastasis. Results: Thirty patients had five different primary sites which were tongue (11), supraglottis (10), glottis (6), hypopharynx (2) and tonsil (1). A total of 40 neck dissections were performed unilaterally in 20 patients and bilaterally in 10 patients. Of these, 16 showed pathologically positive for lymph node metastasis. The sensitivity and specificity of FDG-PET for the diagnosis of cervical metastasis was 75% and 100% respectively, compared with conventional imaging of 56.3% and 95.8%, respectively. The difference of sensitivity was not statistically significant (p=0.453). Of 5 cases with small metastatic node (<1cm), 3 were detected on PET detected correctly but none were detected by CT. Conclusion: FDG-PET was more accurate than conventional imaging study in the diagnosis of metastatic lymph nodes in squamous cell carcinomas of the head and neck, especially detection of small metastatic node. FDG-PET might be useful adjunct to conventional image in the preoperative evaluation of head and neck squamous cell carcinoma.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.47-51
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• 2016

Purpose By ingestion of 18F-FDG of kidney of PET/CT during the inspection, if additional examination is required, depending on whether you want to water intake, we want to confirm a change in the rate of decrease of F-18 FDG of the kidney. Materials and Methods The 80 patients without kidney disease were performed PET/CT examination. Device was analyzed after setting the kidney to a three-dimensional region of interest. In patients require additional examination, and inspection after 30 minutes, a PET/CT torso examination after the water of the 500 cc ingested at a time. After the addition of both water intake group and no hydration group of kidney of SUV, it was compared with PET/CT torso scan. Results High and low of the kidney SUV did not show a significant difference in the rate of decrease. Reduction rates of background (BKG) of additional examination was 2.8% and reduction rates of SUV was 49.7% (Hydration) : -6.8% (No hydration), so did show a significant difference. In the image blind test, the average point score of hydration and no hydration was 34.25 : 17.25. Conclusion An undercurrent of 18F-FDG in the kidney at the time of torso examination, it was confirmed that the reduction rate after the addition of water intake is high. It is considered that can be expected to improve the quality of an image due to a decrease in elongation through the kidneys examination with additional fluid intake as needed intake.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.553-560
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• 2007

Purpose: We evaluated the standard uptake value (SUV) of F-18 FDG at PET/CT for differentiation of benign from malignant tumor in primary musculoskeletal tumors. Materials and Methods: Forty-six tumors (11 benign and 12 malignant soft tissue tumors, 9 benign and 14 malignant bone tumors) were examined with F-18 FDG PET/CT (Discovery ST, GE) prior to tissue diagnosis. The maxSUV(maximum value of SUV) were calculated and compared between benign and malignant lesions. The lesion analysis was based on the transverse whole body image. The maxSUV with cutoff of 4.1 was used in distinguishing benign from malignant soft tissue tumor and 3.05 was used in bone tumor by ROC curve. Results: There was a statistically significant difference in maxSUV between benign (n=11; maxSUV $3.4{\pm}3.2$) and malignant (n=12; maxSUV $14.8{\pm}12.2$) lesions in soft tissue tumor (p=0.001). Between benign bone tumor (n=9; maxSUV $5.4{\pm}4.0$) and malignant bone tumor (n=14; maxSUV $7.3{\pm}3.2$), there was not a significant difference in maxSUV. The sensitivity and specificity for differentiating malignant from benign soft tissue tumor was 83% and 91%, respectively. There were four false positive malignant bone tumor cases to include fibrous dysplasia, Langerhans-cell histiocytosis (n=2) and osteoid osteoma. Also, one false positive case of malignant soft tissue tumor was nodular fasciitis. Conclusion: The maxSUV was useful for differentiation of benign from malignant lesion in primary soft tissue tumors. In bone tumor, the low maxSUV correlated well with benign lesions but high maxSUV did not always mean malignancy.

• 대한핵의학회:학술대회논문집
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• 2000.05a
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• pp.57-57
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• 2000

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.478-481
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• 2008

Reverse redistribution is frequently observed after revascularization in acute myocardial infarction, and usually regarded as a predictor of viable myocardium on stress/rest and 2- to 4-hour redistribution $^{201}Tl$ SPECT. However, there is not enough report of reverse redistribution in case of 24-hour delayed SPECT, which is commonly used for viability assessment. In this report, a case of reverse redistribution on rest and 24-hour delayed $^{201}Tl$ SPECT is reported with use of automatic segmental quantitative analysis. The myocardium of reverse redistribution was dysfunctional on gated SPECT, and diagnosed as non-viable on $^{18}F-FDG$ PET.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.233-240
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• 2004

Purpose: We developed a computer-aided classifier using artificial neural network (ANN) to discriminate the cerebral metabolic pattern of medial and lateral temporal lobe epilepsy (TLE). Materials and Methods: We studied brain F-18-FDG PET images of 113 epilepsy patients sugically and pathologically proven as medial TLE (left 41, right 42) or lateral TLE (left 14, right 16). PET images were spatially transformed onto a standard template and normalized to the mean counts of cortical regions. Asymmetry indices for predefined 17 mirrored regions to hemispheric midline and those for medial and lateral temporal lobes were used as input features for ANN. ANN classifier was composed of 3 independent multi-layered perceptrons (1 for left/right lateralization and 2 for medial/lateral discrimination) and trained to interpret metabolic patterns and produce one of 4 diagnoses (L/R medial TLE or L/R lateral TLE). Randomly selected 8 images from each group were used to train the ANN classifier and remaining 51 images were used as test sets. The accuracy of the diagnosis with ANN was estimated by averaging the agreement rates of independent 50 trials and compared to that of nuclear medicine experts. Results: The accuracy in lateralization was 89% by the human experts and 90% by the ANN classifier Overall accuracy in localization of epileptogenic zones by the ANN classifier was 69%, which was comparable to that by the human experts (72%). Conclusion: We conclude that ANN classifier performed as well as human experts and could be potentially useful supporting tool for the differential diagnosis of TLE.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.363-365
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• 2009

Kikuchi's disease is a self-limiting benign disease characterized by cervical lymphadenopathy, but it can be mistaken for malignant disease, and when involved lymph nodes are unusually located, diagnosis can be more difficult. The authors report the case of a 19-year-old man with Kikuchi's disease, who had isolated intra-abdominal lymphadenopathy and increased 18-fluoro-deoxyglucose (FDG) uptake in positron emission tomography-computed tomography (PET-CT). Although its incidence is extremely rare, intra-abdominal Kikuchi's disease with increased FDG uptake in PET-CT image should be considered in the differential diagnosis when constitutional symptoms mimic those of malignant lymphoma.

• Journal of Yeungnam Medical Science
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• v.25 no.1
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• pp.64-71
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• 2008

Evaluation of a fever of unknown origin (FUO) is complex. Recently, PET scanning has been approved for screening in FUO evaluation. We treated three cases of FUO associated with increased FDG uptake in the bone marrow of the femur and tibia on the fusion PET/CT; all three had the same pattern of uptake. Bone marrow biopsies revealed mature lymphocyte and histiocyte infiltration and myxoid changes in one case, and cortical bone involvement in another case. The cases were all young females who had fever with neutropenia and relative lymphocytosis that lasted for several weeks and then remitted spontaneously. Even though the results of the studies were not diagnostic, the unique uptake pattern on PET/CT and the histology might be related to the cause of the illness and should be studied further to assess the association with classic FUO.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.9-16
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• 2005

Purpose : To prospectively evaluate the use of positron emission tomography with the glucose analog fluoro-deoxyglucose (FDG-PET) to deoxyglucose (FDG-PET) to predict disease-free survival (DFS) after concurrent chemo-radiotherapy (CCRT) in patients with non-disseminated nasopharyngeal carcinoma (NPC). Materials and Methods : We studied 41 patients with non-disseminated NPC scheduled to undergo platinum-based CCRT were eligible for this study. Patients were studied by FDG-PET prior to the CCRT. FDG uptake of tumors were measured with the maximal standardized uptake value (SUV). Results : Complete response rate was $100\%$. In ten patients who presented with any component of treatment failure, the median $SUV_{max}$ was 8.55 (range: $2.49\~14.81$) in any component of failure and the median $SUV_{max}$ was 5.48 (range: $2.31\~26.07$) In the remaining patients without any such failure. Patients having tumors with high FDG uptake had a significantly lower 3-year DFS ($51\%\;{\nu}91\%$, p=0.0070) compared with patients having low uptake tumors. Conclusion : FDG uptake, as measured by the SUV, has potential value in predicting DFS in NPC treated by CCRT, High FDG uptake may be a useful parameter for Identifying patients requiring more aggressive treatment approaches.