Showing posts with label Tatiana Latychevskaia. Show all posts
Showing posts with label Tatiana Latychevskaia. Show all posts

Monday, February 16, 2015

Abstract-Terahertz in-line digital holography of human hepatocellular carcinoma tissue



http://www.nature.com/srep/2015/150213/srep08445/full/srep08445.html

Scientific Reports
 
5,
 
Article number:
 
8445
 
doi:10.1038/srep08445
Received
 
Accepted
 
Published
 



Terahertz waves provide a better contrast in imaging soft biomedical tissues than X-rays, and unlike X-rays, they cause no ionisation damage, making them a good option for biomedical imaging. Terahertz absorption imaging has conventionally been used for cancer diagnosis. However, the absorption properties of a cancerous sample are influenced by two opposing factors: an increase in absorption due to a higher degree of hydration and a decrease in absorption due to structural changes. It is therefore difficult to diagnose cancer from an absorption image. Phase imaging can thus be critical for diagnostics. We demonstrate imaging of the absorption and phase-shift distributions of 3.2 mm × 2.3 mm × 30-μm-thick human hepatocellular carcinoma tissue by continuous-wave terahertz digital in-line holography. The acquisition time of a few seconds for a single in-line hologram is much shorter than that of other terahertz diagnostic techniques, and future detectors will allow acquisition of meaningful holograms without sample dehydration. The resolution of the reconstructions was enhanced by sub-pixel shifting and extrapolation. Another advantage of this technique is its relaxed minimal sample size limitation. The fibrosis indicated in the phase distribution demonstrates the potential of terahertz holographic imaging to obtain a more objective, early diagnosis of cancer.

Sunday, July 13, 2014

Abstract-Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation




Lu Rong, Tatiana Latychevskaia, Dayong Wang, Xun Zhou, Haochong Huang, Zeyu Li, and Yunxin Wang  »View Author Affiliations

http://8.18.37.105/oe/abstract.cfm?uri=oe-22-14-17236


Optics Express, Vol. 22, Issue 14, pp. 17236-17245 (2014)
http://dx.doi.org/10.1364/OE.22.017236

We report here on terahertz (THz) digital holography on a biological specimen. A continuous-wave (CW) THz in-line holographic setup was built based on a 2.52 THz CO2 pumped THz laser and a pyroelectric array detector. We introduced novel statistical method of obtaining true intensity values for the pyroelectric array detector’s pixels. Absorption and phase-shifting images of a dragonfly’s hindwing were reconstructed simultaneously from single in-line hologram. Furthermore, we applied phase retrieval routines to eliminate twin image and enhanced the resolution of the reconstructions by hologram extrapolation beyond the detector area. The finest observed features are 35 μm width cross veins.
© 2014 Optical Society of America

Tuesday, July 8, 2014

Abstract-Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation




http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-22-14-17236
Lu Rong, Tatiana Latychevskaia, Dayong Wang, Xun Zhou, Haochong Huang, Zeyu Li, and Yunxin Wang  »View Author Affiliations

Optics Express, Vol. 22, Issue 14, pp. 17236-17245 (2014)
http://dx.doi.org/10.1364/OE.22.017236

We report here on terahertz (THz) digital holography on a biological specimen. A continuous-wave (CW) THz in-line holographic setup was built based on a 2.52 THz CO2 pumped THz laser and a pyroelectric array detector. We introduced novel statistical method of obtaining true intensity values for the pyroelectric array detector’s pixels. Absorption and phase-shifting images of a dragonfly’s hindwing were reconstructed simultaneously from single in-line hologram. Furthermore, we applied phase retrieval routines to eliminate twin image and enhanced the resolution of the reconstructions by hologram extrapolation beyond the detector area. The finest observed features are 35 μm width cross veins.
© 2014 Optical Society of America