18F-Labelled SF6 and CF4 Production for PET Ventilation Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current positron emission tomography (PET) ventilation studies face limitations due to the short half-life of isotopes like Neon-19 and Nitrogen-13, and existing Fluorine-18 labelled gases are challenging to produce, hindering their widespread use for lung function diagnostics.
Innovation Solution
A process to prepare 18F-labelled sulphur hexafluoride (SF6) and carbon tetrafluoride (CF4) using proton irradiation, which offers a longer half-life and lower water solubility, enabling safer and more effective PET-based ventilation diagnostic studies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Neon-19 or Nitrogen-13 labelled gases are used for PET ventilation studies, then positron emission imaging is enabled, but the very short half-life impairs widespread use and commercialization
Solution Approach 1:
The patent changes the isotopic parameter from short-lived Neon-19 (17.4s) or Nitrogen-13 (9.97min) to Fluorine-18 (109.7min), fundamentally altering the temporal characteristics of the radiotracer to enable practical clinical use while maintaining PET imaging capability
Solution Approach 2:
The patent replaces expensive, short-lived isotopes that require complex production and immediate use with a longer-lived isotope that can be produced more easily and used over an extended period, effectively treating the radiotracer as a more practical, less constrained resource
2Duration of action of moving object
If Fluorine-18 is used to label gases for ventilation PET studies, then longer half-life is achieved, but serious limitations in synthesis have made progress nearly impossible
Solution Approach 1:
The patent uses SF6 and CF4 gases as intermediary compounds that can be readily labeled with Fluorine-18 through established chemical reactions, serving as stable intermediates that bridge the gap between isotope production and clinical application
Solution Approach 2:
The patent changes the chemical composition parameter by selecting specific fluorinated gases (SF6, CF4) that have appropriate chemical reactivity and physical properties for both synthesis and pulmonary ventilation, enabling successful Fluorine-18 labeling
3Adaptability or versatility
If SF6 is labelled with Fluorine-18 for ventilation PET purposes, then the gas can be used for imaging, but existing disclosures teach away from its production
Solution Approach 1:
The patent inverts the conventional approach by not trying to produce 18F-labelled SF6 through direct fluorination reactions (which existing literature discourages), but rather through alternative synthesis pathways that overcome the identified chemical obstacles
4Reliability
If particle-based contrast agents are used for SPECT ventilation studies, then ventilation imaging is achieved, but the agents remain in the lung for a long time which might be a liability in terms of safety
Solution Approach 1:
The patent replaces persistent particle-based contrast agents with short-lived gaseous radiotracers that clear from the lungs rapidly, using the brief presence of the radiotracer (both during imaging and clearance) as a safety feature rather than a limitation
Solution Approach 2:
The patent transitions from particle-based (solid/liquid aerosol) contrast agents to gaseous radiotracers, utilizing the phase difference to achieve rapid pulmonary clearance and improved safety profile while maintaining imaging functionality
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The 18F-labelled SF6 and CF4 compositions provide improved applicability and safety for clinical use, with efficient production and administration, enhancing PET-based ventilation diagnostic capabilities.
Implementation Method 1
Irradiating the gas mixture of step a) with protons with energies from 0.1 to 50 MeV
Data Source
AI summary
There is provided a process for the preparation of a pharmaceutical composition comprising an 18F-labelled gas selected from the group consisting of 18F-labelled sulphur hexafluoride ([18F]SF6) and 18F-labelled carbon tetrafluoride ([18F]CF4), comprising the steps: a) Filling a target with a gas mixture comprising a fluorinated gas selected from the group consisting of sulphur hexafluoride (SF6) and carbon tetrafluoride (CF4); b) Irradiating the gas mixture of step a) with protons with energies from 0.1 to 50 MeV. The pharmaceutical composition obtainable by the process and its uses in diagnosis, prognosis and lung function studies based on positron emission tomography (PET) are also claimed.