APPLICATIONS OF TECHNOLOGY:
- Medical diagnostics
- Biological research involving localization and measurement of radiotracers
- Higher pixel (to 10 µm) and spatial resolution imaging than previously possible
- Real time autoradiography
- Able to detect a wide variety of tracers (e.g., 11C, 14C, 18F, 3H)
- Able to image β- and β+ simultaneously (dual-tracer imaging)
- Naturally registered optical microscopic image and autoradiography
- Quantitative imaging
Scientists at Berkeley Lab have developed an autoradiography-based device to map positron and beta emitting radiotracers with greater pixel and spatial resolution (10–50 µm) than previously possible with traditional autoradiography. The device could be used to localize and quantify molecules of interest—metabolites, receptors, enzymes, or ligands—in sectioned ex vivo tissue biopsies or in microbial samples. The images produced are readily combined with optical images to improve the visualization of markers used to diagnose diseases such as cancer and to study various biological processes.
The advantages of the device over traditional autoradiography stem from the use of digital imaging technologies—either CCD (charge coupled device) or CMOS (complementary metal-oxide-semiconductor) imagers. Like conventional phosphor plate or film screen autoradiography devices, these CCD / CMOS imagers directly detect positron or beta particle emissions with high efficiency—35-38% of the positrons emitted from a sample were imaged in initial tests using 18F. However, they can localize the positron or β- source in the sample with higher spatial resolution than conventional autoradiography imagers (10–50 μm vs. 600 μm). The CCD / CMOS devices also image a segment of the trajectory of each positron or β- rather than just a single point along that trajectory, as in autoradiography. This trajectory information can be extrapolated to more precisely localize the emitting source within the tissue.
This outstanding spatial resolution is not confined to low energy emission from isotopes such as 14C and 3H, but is also obtained with isotopes with higher energy emissions, such as 11C and 18F. As higher energy emissions are usually coupled with shorter half lives, the imaging time can be much shorter (20–30 minutes vs. 10–14 days). These shorter time scales reduce the generation of long lived radioactive waste and may also enable the sequential imaging of metabolic processes. In addition, by detecting the annihilation photons along with the positron trajectory, the device can separate positrons from β-s to perform dual radiotracer (β- and β+) imaging.
Autoradiography has been useful in measuring radiotracers over longer imaging periods in tissue sections and samples of cultured and uncultured microbes. The Berkeley Lab invention combines the advantages of these existing technologies and offers greater spatial resolution and sensitivity. These capabilities will allow for biochemical imaging at cellular and subcellular scales, advancing both research and medical diagnostics.
DEVELOPMENT STAGE: Proven principle.
STATUS: Patent pending. Available for licensing or collaborative research.
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REFERENCE NUMBER: IB-2959