• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.1
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• pp.46-52
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• 2015

Herein we present the synthesis of $^{68}Ga$-labeled gold nanoparticles for in vivo PET imaging. A novel chelator DTPA-Cys was easily prepared from diethylenetriaminepentaacetic dianhydride in high yield. The ${\alpha}_v{\beta}_3$ integrin receptor targeted gold nanoparticle probe was synthesized by using DTPA-Cys, polyethylene glycol and cRGD peptide. $^{68}Ga$ labeling of cRGD conjugated gold nanoparticle was carried out at $40^{\circ}C$ for 30 min. Observed radiochemical yield was more than 75% as determined by radio-TLC and the probe was purified by centrifugation. In vitro stability test showed that 90% of $^{68}Ga$-labeled gold nanoparticle probe was stable in FBS for 1 h. Those results demonstrated that $^{68}Ga$-labeled gold nanoparticle could be used as a potentially useful probe for specific tumor imaging.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.175-179
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• 2004

Molecular nuclear cardiac imaging has included Tc-99m Annexin imaging to visualize myocardial apoptosis, but is now usually associated with gene therapy and cell-based therapy. Cardiac gene therapy was not successful so far but cardiac reporter gene imaging was made possible using HSV-TK (herpes simplex virus thymidine kinase) and F-18 FHBG (fluoro-hydroxymethylbutyl guanine) or I-124 FIAU (fluoro-deoxyiodo-arabino-furanosyluracil). Gene delivery was performed by needic injection with or without catheter guidance. Tk expression did not last longer than 2 weeks in myocardium. Cell-based therapy of ischemic heart or failing heart looks promising, but biodistribution and differentiation of transplanted cells are not known. Reporter genes can be transfected to the stem/progenitor cells and cells containing these genes can be transplanted to the recipients using catheter-based purging or injection. Repeated imaging should be available and if promoter are varied to let express reporter transgenes, cellular (trans)differentiation can be studied. NIS (sodium iodide symporter) or D2R receptor genes are promising in this aspect.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.172-180
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• 2008

PET/CT fused image with anatomical and functional information have improved medical diagnosis and interpretation. This fusion has resulted in more precise localization and characterization of sites of radio-tracer uptake. However, a motion during whole-body imaging has been recognized as a source of image quality degradation and reduced the quantitative accuracy of PET/CT study. The respiratory motion problem is more challenging in combined PET/CT imaging. In combined PET/CT, CT is used to localize tumors and to correct for attenuation in the PET images. An accurate spatial registration of PET and CT image sets is a prerequisite for accurate diagnosis and SUV measurement. Correcting for the spatial mismatch caused by motion represents a particular challenge for the requisite registration accuracy as a result of differences in PET/CT image. This paper provides a brief summary of the materials and methods involved in multiple investigations of the correction for respiratory motion in PET/CT imaging, with the goal of improving image quality and quantitative accuracy.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.401-409
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• 2008

Purpose: Recently multi-modal imaging system has become widely adopted in molecular imaging. We tried to fabricate animal-specific positioning molds for PET/MR fusion imaging using easily available molding clay and rapid foam. The animal-specific positioning molds provide immobilization and reproducible positioning of small animal. Herein, we have compared fiber-based molding clay with rapid foam in fabricating the molds of experimental animal. Materials and Methods: The round bottomed-acrylic frame, which fitted into microPET gantry, was prepared at first. The experimental mice was anesthetized and placed on the mold for positioning. Rapid foam and fiber-based clay were used to fabricate the mold. In case of both rapid foam and the clay, the experimental animal needs to be pushed down smoothly into the mold for positioning. However, after the mouse was removed, the fabricated clay needed to be dried completely at $60^{\circ}C$ in oven overnight for hardening. Four sealed pipet tips containing $[^{18}F]FDG$ solution were used as fiduciary markers. After injection of $[^{18}F]FDG$ via tail vein, microPET scanning was performed. Successively, MRI scanning was followed in the same animal. Results: Animal-specific positioning molds were fabricated using rapid foam and fiber-based molding clay for multimodality imaging. Functional and anatomical images were obtained with microPET and MRI, respectively. The fused PET/MR images were obtained using freely available AMIDE program. Conclusion: Animal-specific molds were successfully prepared using easily available rapid foam, molding clay and disposable pipet tips. Thanks to animal-specific molds, fusion images of PET and MR were co-registered with negligible misalignment.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.2 no.2
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• pp.69-72
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• 2016

Since the translocator protein (TSPO) is involved in neurodegeneration diseases, many scientists' interest has been focused on the development of a ligand targeting TSPO. A novel compound based on pyrazolo[1,5 -a] pyrimidine structure, DPA-714, has been studied and considered as a TSPO ligand with high affinity. In this highlight review, several researches for the novel radioligand for the translocator protein are illustrated.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.1
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• pp.39-45
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• 2020

Recently, single-domain antibodies (sdAb) are bioengineered for molecular imaging applications. Single-domain antibody, obtained from naturally occurring antibodies in camelid species and cartilaginous fish is the smallest fully functional antigen-binding antibody fragments of heavy-chain. Since their discovery, they have been investigated extensively in clinical therapeutics, monitoring and diagnostics. Their small size is important advantage for high solubility, high stability, fast blood clearance and rapid targeting. This review article summarizes the recent status of this new antibody to visualize, diagnose or inhibit specific targets of cancer.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.95-97
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• 2015

The translocator protein (TSPO) is one of the important targets for Positron Emission Tomography (PET) imaging because it is associated with brain cancer, stroke, and neurodegeneration. Recently, a novel quinoline compound with high affinity agent for the translocator protein has been developed. In this highlight review, major studies for the quinoline compound are described.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.1
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• pp.41-49
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• 2021

Diversity and flexibility are two typical hallmarks of macrophages. Two types of macrophages, M1(classically activated macrophages) and M2(alternatively activated macrophages) exist at both ends of the commonly known macrophage polarization. M1 macrophages have inflammatory properties and are primarily responsible for defending against invading bacteria in our body. On the other hand, M2 macrophages are involved in anti-inflammatory responses and tissue remodeling. Polarized migration of macrophages is of increasing interest in regulating the initiation, generation, and resting phases of inflammatory diseases. In this review, it intend to discuss the properties and functions of tumor-associated macrophages based on polarized macrophages that affect inflammatory diseases. In addition, the purpose of this study is to investigate a molecular imaging approach that targets macrophages that affect tumor growth by controlling the polarization of macrophages that affect tumor diagnosis and treatment.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.140-148
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• 2008

$^{18}F-FDG$ PET showed a high sensitivity and specificity in the initial staging of malignant melanoma, and it also predicted the prognosis correctly. In addition, it had a higher sensitivity and specificity in the detection of recurrence and restaging than conventional imaging modalities. Meanwhile, there's less clinical evidence to support the use of $^{18}F-FDG$ PET in the response evaluation for chemotherapy and the diagnosis/differential diagnosis of malignant melanoma.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.150-153
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• 2009

Xanthogranulomatous pyelonephritis is an uncommon chronic renal infection, which is usually found on middle-aged women and is rare in infant. Sometimes it forms focal mass like lesion of kidney with pathologically characteristic lipid-laden macrophage. A 1-month female infant was admitted for fever and moaning sound. On work-up of urinary tract infection, abdomen ultrasonography and computed tomography revealed a large mass on the upper portion of right kidney and PET/CT showed homogeneously increased $^{18}F$-FDG uptake. The radical nephrectomy of right kidney was performed and histology revealed a focal xanthogranulomatous pyelonephritis. To our knowledge, this is the first report presenting the finding of $^{18}F$-FDG PET/CT in the childhood xanthogranulomatous pyelonephritis.