• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.1-5
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• 2008

Primary brain tumor accounts for 1.4% of entire cancer. For males between the ages of 15 and 34 years, central nervous system tumors account for the leading cause of cancer death. $^{18}F-FDG$ PET has been reported that it can provide important diagnostic information relating to tumor grading and differentiation from non- tumorous condition. In addition, the degree of FDG metabolism carries prognostic significance. By mapping the metabolic pattern of heterogeneous tumors, $^{18}F-FDG$ PET can aid in targeting for stereotactic biopsy by selecting the subregions within the tumor that are most hypermetabolic and potentially have the highest grade. According to clinical research data, FOG PET is expected to be a helpful diagnostic tool in the management of brain tumors.

• The Korean Journal of Nuclear Medicine
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• v.36 no.2
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• pp.143-145
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• 2002

A 49-year-old male patient with a carcinoma of the right pyriform sinus had a whole-body bone scan and gamma camera based F-18 FDG-PET for staging. Tc-99m MDP bone scan depicted diffuse increased uptake in the left femur due to chronic osteomyelitis but no skeletal metastasis. F-18-FDG-PET revealed increased focal bone uptake and uptake in the draining sinus due to chronic osteomyelitis in addition to visualization of the right pyriform sinus carcinoma and right neck nodal uptake. Fluorine-18 fluorodeoxyglucose-positron emission tomography is significantly more accurate than the bone scan in pinpointing chronic osteomyelitis focus and draining soft tissue infection.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3243-3248
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• 2013

The tissue inhibitor of metalloproteinase-2 (TIMP-2) inhibits matrix metalloproteinases activity and modulates cellular proliferation and apoptosis. The human serum albumin-TIMP-2 with folic acid conjugate (termed HT2-folate) was synthesized to promote uptake through folate receptors (FRs), and a corresponding radio-labeled compound was prepared for tumor diagnosis by positron emission tomography (PET). $^{68}Ga$-NOTA-HT2-folate was synthesized from $^{68}Ga$ and the NOTA chelator with HT2-folate. The fusion protein was identified using MALDI-TOF mass spectrometry. The radioligand was prepared with a high radiochemical yield. Cell-surface association of $^{68}Ga$-NOTA-HT2-folate significantly increased over time in FR-positive tumor cells. In animal PET and biodistribution studies, tumor uptake was very high as early as 1 h after radioligand injection. Folate conjugation enhanced the selective receptor-targeting efficacy of HT2 in FRexpressing tumors, and its radioligand will be useful as an in vitro tool and for in vivo tumor diagnosis by PET imaging.

• Clinical and Experimental Pediatrics
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• v.57 no.5
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• pp.226-231
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• 2014

Purpose: Kikuchi-Fujimoto disease (KFD) is a benign disease, which is characterized by a cervical lymphadenopathy with fever, and it often mimics malignant lymphoma (ML). 2-[$^{18}F$]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ($^{18}F$-FDG PET/CT) is a powerful imaging modality for the diagnosis, staging and monitoring of ML, with the limitations including the nonspecific FDG uptake in infectious or inflammatory processes. This study compared clinical manifestations and PET/CT findings between KFD and ML patients. Methods: We retrospectively reviewed the medical records of 23 patients with KFD and 33 patients with ML, diagnosed histopathologically, between January 2000 and May 2013 at the Department of Pediatrics, Yeungnam University Medical Center. Among them, we analyzed the clinical manifestations, laboratory findings and characteristics, and the amount of $^{18}F$-FDG uptake between 8 KFD and 9 ML patients who had $^{18}F$-FDG PET/CT. Results: The $^{18}F$-FDG PET/CT maximum standardized uptake values ($SUV_{max}$) ranged from 8.3 to 22.5 (mean, 12.0) in KFDs, and from 5.8 to 34.3 (mean, 15.9) in MLs. There were no significant differences in $SUV_{max}$ between KFDs and MLs. $^{18}F$-FDG PET/CT with ML patients showed hot uptakes in the extranodal organs, such as bone marrow, small bowel, thymus, kidney, orbit and pleura. However, none of the KFD cases showed extranodal uptake (P<0.001). $^{18}F$-FDG PET/CT findings of KFD with nodal involvement only were indistinguishable from those of ML. Conclusion: Patients who had extranodal involvement on PET/CT were more likely to have malignancy than KFD.

• Korean Journal of Radiology
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• v.25 no.3
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• pp.243-256
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• 2024

Objective: We aimed to investigate whether 2-[¹⁸F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (2-[¹⁸F]FDG PET/CT) can aid in evaluating the risk of malignancy in ampullary tumors detected by endoscopy. Materials and Methods: This single-center retrospective cohort study analyzed 155 patients (79 male, 76 female; mean age, 65.7 ± 12.7 years) receiving 2-[¹⁸F]FDG PET/CT for endoscopy-detected ampullary tumors 5-87 days (median, 7 days) after the diagnostic endoscopy between June 2007 and December 2020. The final diagnosis was made based on histopathological findings. The PET imaging parameters were compared with clinical data and endoscopic features. A model to predict the risk of malignancy, based on PET, endoscopy, and clinical findings, was generated and validated using multivariable logistic regression analysis and an additional bootstrapping method. The final model was compared with standard endoscopy for the diagnosis of ampullary cancer using the DeLong test. Results: The mean tumor size was 17.1 ± 7.7 mm. Sixty-four (41.3%) tumors were benign, and 91 (58.7%) were malignant. Univariable analysis found that ampullary neoplasms with a blood-pool corrected peak standardized uptake value in earlyphase scan (SUVe) ≥ 1.7 were more likely to be malignant (odds ratio [OR], 16.06; 95% confidence interval [CI], 7.13-36.18; P < 0.001). Multivariable analysis identified the presence of jaundice (adjusted OR [aOR], 4.89; 95% CI, 1.80-13.33; P = 0.002), malignant traits in endoscopy (aOR, 6.80; 95% CI, 2.41-19.20; P < 0.001), SUVe ≥ 1.7 in PET (aOR, 5.43; 95% CI, 2.00-14.72; P < 0.001), and PET-detected nodal disease (aOR, 5.03; 95% CI, 1.16-21.86; P = 0.041) as independent predictors of malignancy. The model combining these four factors predicted ampullary cancers better than endoscopic diagnosis alone (area under the curve [AUC] and 95% CI: 0.925 [0.874-0.956] vs. 0.815 [0.732-0.873], P < 0.001). The model demonstrated an AUC of 0.921 (95% CI, 0.816-0.967) in candidates for endoscopic papillectomy. Conclusion: Adding 2-[¹⁸F]FDG PET/CT to endoscopy can improve the diagnosis of ampullary cancer and may help refine therapeutic decision-making, particularly when contemplating endoscopic papillectomy.

• Journal of the Korean Society of Radiology
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• v.79 no.6
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• pp.348-353
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• 2018

Hepatic pseudolymphoma is a rare benign liver mass that is characterized by proliferation of non-neoplastic lymphocytes extranodally. To the best of our knowledge, only 46 cases have been reported in the English literature. We described the case of a 75-year-old woman with hepatic pseudolymphoma mimicking a hypervascular tumor. After the histological confirmation of the rectal neuroendocrine tumor, CT scan revealed a 1.0 cm-sized, poorly-defined and low-density nodule in the liver. On MRI, the hepatic nodule showed an arterial enhancement and a low-signal intensity on the hepatobiliary phase. On diffusion-weighted imaging, the hepatic nodule showed a high signal intensity on a high b-value. On fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT, it revealed a high standardized uptake value nodule. The US showed the hypoechoic nodule and the US-guided biopsy confirmed the hepatic pseudolymphoma.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.98-111
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• 2008

This review introduces advances in clinical and pre-clinical single photon emission computed tomography (SPECT) and positron emission tomography (PET) providing noninvasive functional images of biological processes. Development of new collimation techniques such as multi-pinhole and slit-slat collimators permits the improvement of system spatial resolution and sensitivity of SPECT. Application specific SPECT systems using smaller and compact solid-state detector have been customized for myocardial perfusion imaging with higher performance. Combined SPECT/CT providing improved diagnostic and functional capabilities has been introduced. Advances in PET and CT instrumentation have been incorporated in the PET/CT design that provide the metabolic information from PET superimposed on the anatomic information from CT. Improvements in the sensitivity of PET have achieved by the fully 3D acquisition with no septa and the extension of axial field-of-view. With the development of faster scintillation crystals and electronics, time-of-flight (TOF) PET is now commercially available allowing the increase in the signal-to-noise ratio by incorporation of TOF information into the PET reconstruction process. Hybrid PET/SPECT/CT systems has become commercially available for molecular imaging in small animal models. The pre-clinical systems have improved spatial resolution using depth-of-interaction measurement and new collimators. The recent works on solid state detector and dual modality nuclear medicine instrumentations incorporating MRI and optical imagers will also be discussed.

• Annals of Clinical Neurophysiology
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• v.22 no.1
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• pp.37-40
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• 2020

Neurolymphomatosis (NL) is characterized by the infiltration of malignant lymphoma cells into peripheral nerves, nerve roots, plexuses, or cranial nerves. This is a very rare complication of mantle-cell lymphoma. Diagnosing NL is made difficult by cerebrospinal fluid cytology and bone-marrow biopsy results often being negative. NL can appear as the only sign of recurrence in a patient with a previous diagnosis of lymphoma. Here we present two cases of NL in patients with mantle-cell lymphoma diagnosed by positron emission tomography with deoxy-fluoro-D-glucose integrated with computed tomography.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.582-587
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• 2009

A 59-year-old woman who was diagnosed with malignant pheochromocytoma underwent $^{18}F$-fluorodeoxyglucose positron emission tomography/computed tomography ($^{18}F$-FDG PET/CT). She had undergone left adrenalectomy for pheochromocytoma 4 years previously. Recent multiple metastatic pulmonary nodules were noted on the chest X-ray. After treatment with $^{131}I$-metaiodobenzylguanidine ($^{131}I$-MIBG) with 7.4 GBq, post-therapy $^{131}I$-MIBG scintigraphy depicted multiple distant metastases including lung, liver, abdominal para-aortic and mesenteric lymph nodes. $^{18}F$-FDG PET/CT also depicted multiple metastases in lung, liver, and abdominal para-aortic lymph nodes, but some lesions were not shown. In this case, $^{131}I$-MIBG scintigraphy found additional lesions in metastatic malignant pheochromocytoma.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.80-87
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• 2015

Carbon-fluorine (C-F) bonds have been found ubiquitously in pharmaceuticals, radiopharmaceuticals, agrochemicals, and material science due to their unique properties such as thermal and oxidative stability and lipophilicity to improve bioavailability. For the past five years, there have been significant advances in F-18 fluorination of aromatic complex molecules combined with the development of late-stage fluorination reactions. More recently, direct incorporation of F-18 to fluorinated aromatic molecules via borylation of C-F bonds has been developed by Niwa and Hosoya. In this minireview, we will discuss the progress of C-F bondborylation of fluorinated arenes utilizing transition metal catalysts and the impact on the development of F-18 radiotracers for positron emission tomography (PET).