Language
Country/Area
No result found
The super secret of oxygen-18: How to make it the key to PET scans?!
Oxygen-18 (18O) is a naturally occurring stable isotope and belongs to the category of environmental isotopes. As one of the important precursors of positron emission tomography (PET), the application field of oxygen-18 is remarkable. Its main use is in the production of fluorodeoxyglucose (FDG), a common radiopharmaceutical that is important for diagnosing cancer and other diseases.
Generally speaking, in the radiopharmaceutical industry, enriched water (H2Ω) is bombarded with hydrogen ions to produce fluorine-18. This element is then synthesized into FDG and injected into the patient.
One of the core of these processes comes from the operation of the Oxygen-18 Lightweighting Plant. In these plants, large quantities of oxygen-18-enriched water are used to rapidly generate 18F-labeled fluorodeoxyglucose (FDG) in PET scanning centers. In medical imaging technology, the image quality of positron emission tomography is crucial, so the demand for oxygen-18 is increasing.
Use of oxygen-18 in paleoclimatology
The applications of oxygen-18 are not limited to the medical field. In ice core studies, primarily from Arctic and Antarctic ice cores, the ratio of oxygen-18 to 16O (called δ18O) can be used to study temperature changes in ancient precipitation. If we assume that there have been no significant changes in polar atmospheric circulation and altitude, we can use the temperature at which the ice formed to estimate the climate conditions at the time.
The nitrogen cycle also plays an important role in this process, with oxygen isotope ratios showing a corresponding fractional removal as temperature changes.
In the 1950s, scientist Harold Urey conducted an experiment in which he mixed ordinary water with water containing oxygen-18 in a bucket and partially froze it to help study the changes in the distribution of this isotope and its effects on the environment. Impact on climate.
Plant Physiology and Oxygen-18
In addition to paleoclimatology, oxygen-18 has also played an important role in the study of plant physiology. By labeling the oxygen-18 in the atmosphere, it is possible to measure the amount of oxygen absorbed by plants during photorespiration. The study shows that long before industrialization, most plants reabsorbed half of the oxygen produced by photosynthesis through photorespiration.
The study suggests that the presence of oxygen may have halved the productivity of plants at the time in terms of photosynthesis.
Production process of fluorine-18
Fluorine-18 is produced by bombarding 18O-enriched water with high-energy protons. Protons of about 18 MeV are used in this process. Such a process ultimately results in a fluoride solution, which is a key material for the synthesis of various radiopharmaceuticals.
The prepared radiopharmaceuticals must then be synthesized because high-energy proton radiation would likely destroy the molecules.
Due to the short half-life of fluorine-18, PET scanning centers need to synthesize and use the drug quickly. Taking fluorodeoxyglucose as an example, its production cycle usually does not exceed 90 minutes, which greatly improves diagnostic efficiency.
SummaryThese mysterious applications of oxygen-18 make it play an indispensable role in both scientific research and clinical diagnosis. It not only promotes the development of paleoclimatology and helps scientists understand the historical changes of the earth; it also becomes a key imaging tool in modern medicine. Have you ever thought about how future medical technology will further expand oxygen-18? What is the application scope?
