Time‐gated imaging in planar and tomographic x‐ray imaging

Abstract

Time-gated imaging is a new technique for scatter suppression in radiological imaging, based on the use of ultrashort x-ray pulses in combination with a fast gatable detector. We demonstrate scatter suppression in both planar and computed tomography ͑CT͒ radiography in an experimental model using x rays from a laser-produced plasma. The scatter-suppression efficiency of time-gated imaging is found to be similar to existing standard techniques. Furthermore, it allows for a potential decrease in patient dose. Monte-Carlo simulations confirm these results. We present an overview including theoretical simulations, experimental studies and comparisons to established techniques. The current technical limitations are evaluated and possible future applications in volumetric CT imaging are discussed.

Some applications of ultrashort laser pulses in biology and medicine

“…By restricting the imaging to the ballistic photons only, contrast is enhanced. Recently, the gated-viewing concept has been combined with tomographic back-projection to yield scatter-reduced twodimensional images of tissue phantoms (See figure 9) [39,40].…”

Ultrashort X-ray source driven by femtosecond laser pulses

“…In fig. 3 the available experimental results on the average hard-Xray dose rates obtained by different groups are summarized [1][2][3][4][5]. To present these data in one plot, the experimental dose rates D(R), recorded at different distances R from the radiation sources, were adapted to a 10 cm distance by multiplying them by a factor of (R/10 cm) 2 .…”

“…Ultrashort hard-X-rays are currently generated by focusing high-power (terawatt) femtosecond laser radiation onto a solid target [1][2][3][4][5]. During the high-intensity laser-matter interaction a hot plasma, very energetic electrons, and ultrashort hard-X-ray pulses are produced.…”

Time-gated x-ray tomography

“…Significantly higher contrast improvements are expected for thicker, more realistic scattering volumes. 13 In a conventional CT machine, in contrast to our experimental setup, the radiation is limited to a thin slice of tissue to reduce scattering from neighboring tissue. Additionally, anti-scatter grids are used, imposing an unwanted dose penalty.…”