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Textitis as Seen on 18F-NaF Imaging Using an Ultra-High-Resolution Positron Emission Mammography Scanner

Usmani S, Rasheed R, Al Kandari F

J Nucl Med Technol, 2020 Jun;48(2):181-183.
PMID: 32111663 DOI: 10.2967/jnmt.119.235986

Textitis is a new term used to refer to the degenerative-strain osteoarthritis that comes from excessive use of a smart phone. 18F-NaF is increasingly used in diagnosing skeletal pain that is not identified on radiographs. We report a case of a 26-y-old woman with left breast cancer referred for 18F-NaF PET/CT, who was complaining of right thumb and wrist pain. Findings were negative for bone secondaries. Dedicated hands views were acquired on a positron emission mammography scanner and showed focal uptake at the first carpometacarpal and second metacarpophalangeal joints. On the basis of the strong history, the findings were likely due to active arthritic changes caused by repetitive strain injury from excessive text messaging.

Matched MeSH terms: Fluorine Radioisotopes*
Fulltext New Diethyl Ammonium Salt of Thiobarbituric Acid Derivative: Synthesis, Molecular Structure Investigations and Docking Studies

Barakat A, Al-Majid AM, Soliman SM, Lotfy G, Ghabbour HA, Fun HK, et al.

Molecules, 2015;20(11):20642-58.
PMID: 26610441 DOI: 10.3390/molecules201119710

The synthesis of the new diethyl ammonium salt of diethylammonium(E)-5-(1,5-bis(4-fluorophenyl)-3-oxopent-4-en-1-yl)-1,3-diethyl-4,6-dioxo-2-thioxohexaydropyrimidin-5-ide 3 via a regioselective Michael addition of N,N-diethylthiobarbituric acid 1 to dienone 2 is described. In 3, the carboanion of the thiobarbituric moiety is stabilized by the strong intramolecular electron delocalization with the adjacent carbonyl groups and so the reaction proceeds without any cyclization. The molecular structure investigations of 3 were determined by single-crystal X-ray diffraction as well as DFT computations. The theoretically calculated (DFT/B3LYP) geometry agrees well with the crystallographic data. The effect of fluorine replacement by chlorine atoms on the molecular structure aspects were investigated using DFT methods. Calculated electronic spectra showed a bathochromic shift of the π-π* transition when fluorine is replaced by chlorine. Charge decomposition analyses were performed to study possible interaction between the different fragments in the studied systems. Molecular docking simulations examining the inhibitory nature of the compound show an anti-diabetic activity with Pa (probability of activity) value of 0.229.

Matched MeSH terms: Fluorine
Effect of annealing temperatures on TiO2 thin films prepared by spray pyrolysis deposition method

Fazli FIM, Nayan N, Ahmad MK, Mohd Napi Ml, Hamed NKA, Khalid NS

Sains Malaysiana, 2016;45:1197-1200.

Titanium dioxide (TiO2
) nanoparticles thin film has been successfully synthesized by a spray pyrolysis deposition method
by using an air compressor on a fluorine-doped tin oxide (FTO) substrate and was annealed at different temperature. TiO2
is the most common oxide as an electrode in dye sensitized solar cell (DSSC) which still has chances of improvements to
increase its efficiency as an electrode. The efficiency of a DSSC was relatively low but modifications on every part of a
DSSC were currently in research progress and an increase in adsorbed dye molecules was considered a potential. Thus,
the influences of annealing temperature on structural and morphological properties of TiO2
have been studied using
X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively, while the efficiency of
the films in a solar cell was studied by a solar simulator. The FESEM result showed several degrees of porosity obtained
by varying the annealing temperature. The crystallinity of TiO2 investigated by XRD showed that the crystallinity of the
TiO2
thin films was generally unaffected by the annealing temperature. The relationship between the properties and the
efficiency of the films as an electrode was also studied

Matched MeSH terms: Fluorine
Fulltext Fluorine-19 Magnetic Resonance Imaging for Detection of Amyloid β Oligomers Using a Keto Form of Curcumin Derivative in a Mouse Model of Alzheimer's Disease

Yanagisawa D, Ibrahim NF, Taguchi H, Morikawa S, Tomiyama T, Tooyama I

Molecules, 2021 Mar 04;26(5).
PMID: 33806326 DOI: 10.3390/molecules26051362

Recent evidence suggests that the formation of soluble amyloid β (Aβ) aggregates with high toxicity, such as oligomers and protofibrils, is a key event that causes Alzheimer's disease (AD). However, understanding the pathophysiological role of such soluble Aβ aggregates in the brain in vivo could be difficult due to the lack of a clinically available method to detect, visualize, and quantify soluble Aβ aggregates in the brain. We had synthesized a novel fluorinated curcumin derivative with a fixed keto form, named as Shiga-Y51, which exhibited high selectivity to Aβ oligomers in vitro. In this study, we investigated the in vivo detection of Aβ oligomers by fluorine-19 (19F) magnetic resonance imaging (MRI) using Shiga-Y51 in an APP/PS1 double transgenic mouse model of AD. Significantly high levels of 19F signals were detected in the upper forebrain region of APP/PS1 mice compared with wild-type mice. Moreover, the highest levels of Aβ oligomers were detected in the upper forebrain region of APP/PS1 mice in enzyme-linked immunosorbent assay. These findings suggested that 19F-MRI using Shiga-Y51 detected Aβ oligomers in the in vivo brain. Therefore, 19F-MRI using Shiga-Y51 with a 7 T MR scanner could be a powerful tool for imaging Aβ oligomers in the brain.

Matched MeSH terms: Fluorine-19 Magnetic Resonance Imaging/methods*
Fulltext Synthesis of [18F]F-γ-T-3, a Redox-Silent γ-Tocotrienol (γ-T-3) Vitamin E Analogue for Image-Based In Vivo Studies of Vitamin E Biodistribution and Dynamics

Roselt P, Cullinane C, Noonan W, Elsaidi H, Eu P, Wiebe LI

Molecules, 2020 Dec 03;25(23).
PMID: 33287202 DOI: 10.3390/molecules25235700

Vitamin E, a natural antioxidant, is of interest to scientists, health care pundits and faddists; its nutritional and biomedical attributes may be validated, anecdotal or fantasy. Vitamin E is a mixture of tocopherols (TPs) and tocotrienols (T-3s), each class having four substitutional isomers (α-, β-, γ-, δ-). Vitamin E analogues attain only low concentrations in most tissues, necessitating exacting invasive techniques for analytical research. Quantitative positron emission tomography (PET) with an F-18-labeled molecular probe would expedite access to Vitamin E's biodistributions and pharmacokinetics via non-invasive temporal imaging. (R)-6-(3-[18F]Fluoropropoxy)-2,7,8-trimethyl-2-(4,8,12-trimethyltrideca-3,7,11-trien-1-yl)-chromane ([18F]F-γ-T-3) was prepared for this purpose. [18F]F-γ-T-3 was synthesized from γ-T-3 in two steps: (i) 1,3-di-O-tosylpropane was introduced at C6-O to form TsO-γ-T-3, and (ii) reaction of this tosylate with [18F]fluoride in DMF/K222. Non-radioactive F-γ-T-3 was synthesized by reaction of γ-T-3 with 3-fluoropropyl methanesulfonate. [18F]F-γ-T-3 biodistribution in a murine tumor model was imaged using a small-animal PET scanner. F-γ-T-3 was prepared in 61% chemical yield. [18F]F-γ-T-3 was synthesized in acceptable radiochemical yield (RCY 12%) with high radiochemical purity (>99% RCP) in 45 min. Preliminary F-18 PET images in mice showed upper abdominal accumulation with evidence of renal clearance, only low concentrations in the thorax (lung/heart) and head, and rapid clearance from blood. [18F]F-γ-T-3 shows promise as an F-18 PET tracer for detailed in vivo studies of Vitamin E. The labeling procedure provides acceptable RCY, high RCP and pertinence to all eight Vitamin E analogues.

Matched MeSH terms: Fluorine Radioisotopes/pharmacokinetics; Fluorine Radioisotopes/chemistry*
The quantification of PET-CT radiotracers to determine minimal scan time using quadratic formulation

Said MA, Musarudin M, Zulkaffli NF

Ann Nucl Med, 2020 Dec;34(12):884-891.
PMID: 33141408 DOI: 10.1007/s12149-020-01543-x

OBJECTIVE: 18F is the most extensively used radioisotope in current clinical practices of PET imaging. This selection is based on the several criteria of pure PET radioisotopes with an optimum half-life, and low positron energy that contributes to a smaller positron range. In addition to 18F, other radioisotopes such as 68Ga and 124I are currently gained much attention with the increase in interest in new PET tracers entering the clinical trials. This study aims to determine the minimal scan time per bed position (Tmin) for the 124I and 68Ga based on the quantitative differences in PET imaging of 68Ga and 124I relative to 18F.
METHODS: The European Association of Nuclear Medicine (EANM) procedure guidelines version 2.0 for FDG-PET tumor imaging has adhered for this purpose. A NEMA2012/IEC2008 phantom was filled with tumor to background ratio of 10:1 with the activity concentration of 30 kBq/ml ± 10 and 3 kBq/ml ± 10% for each radioisotope. The phantom was scanned using different acquisition times per bed position (1, 5, 7, 10 and 15 min) to determine the Tmin. The definition of Tmin was performed using an image coefficient of variations (COV) of 15%.
RESULTS: Tmin obtained for 18F, 68Ga and 124I were 3.08, 3.24 and 32.93 min, respectively. Quantitative analyses among 18F, 68Ga and 124I images were performed. Signal-to-noise ratio (SNR), contrast recovery coefficients (CRC), and visibility (VH) are the image quality parameters analysed in this study. Generally, 68Ga and 18F gave better image quality as compared to 124I for all the parameters studied.
CONCLUSION: We have defined Tmin for 18F, 68Ga and 124I SPECT CT imaging based on NEMA2012/IEC2008 phantom imaging. Despite the long scanning time suggested by Tmin, improvement in the image quality is acquired especially for 124I. In clinical practice, the long acquisition time, nevertheless, may cause patient discomfort and motion artifact.

Matched MeSH terms: Fluorine Radioisotopes/chemistry
18F-PSMA-1007 PET/CT for Initial Staging of Renal Cell Carcinoma in an End-Stage Renal Disease Patient

Marafi F, Sasikumar A, Aldaas M, Esmail A

Clin Nucl Med, 2021 Jan;46(1):e65-e67.
PMID: 33181733 DOI: 10.1097/RLU.0000000000003354

A 46-year-old man with end-stage renal disease and renal cell carcinoma underwent F-FDG PET/CT for initial staging followed by F-PSMA-1007 PET/CT. Unlike F-FDG, which undergoes renal clearance, F-PSMA-1007 undergoes hepatobiliary clearance and thus generates superior quality images. F-PSMA-1007 PET/CT showed intense tracer-avid left renal mass lesion (FDG nonavid); lytic bone lesions (FDG avid) and single liver lesion (FDG nonavid). This case highlights the superiority of F-PSMA-1007 over F-FDG PET/CT in identifying primary lesion as well as metastatic sites in case of renal cell carcinoma even in the presence of end-stage renal disease.

Matched MeSH terms: Fluorine Radioisotopes