Fiber-probe detection for positron-emission-assisted Cherenkov-radiation brain mapping

Suitably designed optical fibers are shown to offer a powerful tool for functional brain mapping, facilitating the detection of Cherenkov radiation generated by relativistic positrons from positron-emitting radionuclides. Fiber probes support a low-loss delivery of the high-intensity short-wavelength part of the Cherenkov spectrum, which is strongly absorbed by biotissues, and lower the threshold positron energy ε required for Cherenkov radiation relative to ε values typical of biotissues, thus enhancing the conversion of positron energy into Cherenkov radiation.

Figure 1

Detection of positron-emission-induced Cherenkov radiation with a fiber probe.

Figure 2

Attenuation spectra of an optical fiber (solid line) and brain tissue (dashed line). The spectrum of Cherenkov-radiation intensity is shown by the dotted line.

Figure 3

Spectra of Cherenkov radiation transmitted through an optical fiber with the length $l_f$ = 1 m (solid line) and brain tissue with the length $l_f$ = 10 cm (dashed line) and 3 cm (dotted line).