Impulse response correction enables high-resolution clinical hand-held optoacoustics

2021 ◽  
Author(s):  
Dominik Justel ◽  
Kaushik Basak Chowdhury ◽  
Maximilian Bader ◽  
Christoph Dehner ◽  
Vasilis Ntziachristos
2020 ◽  
Vol 8 (1) ◽  
pp. SA49-SA61
Author(s):  
Huihuang Tan ◽  
Donghong Zhou ◽  
Shengqiang Zhang ◽  
Zhijun Zhang ◽  
Xinyi Duan ◽  
...  

Amplitude-variation-with-offset (AVO) technique is one of the primary quantitative hydrocarbon discrimination methods with prestack seismic data. However, the prestack seismic data are usually have low data quality, such as nonflat gathers and nonpreserved amplitude due to absorption, attenuation, and/or many other reasons, which usually lead to a wrong AVO response. The Neogene formations in the Huanghekou area of the Bohai Bay Basin are unconsolidated clastics with a high average porosity, and we find that the attenuation on seismic signal is very strong, which causes an inconsistency of AVO responses between seismic gathers and its corresponding synthetics. Our research results indicate that the synthetic AVO response can match the field seismic gathers in the low-frequency end, but not in the high-frequency components. Thus, we have developed an AVO response correction method based on high-resolution complex spectral decomposition and low-frequency constraint. This method can help to achieve a correct high-resolution AVO response. Its application in Bohai oil fields reveals that it is an efficient way to identify hydrocarbons in rocks, which provides an important technique for support in oil and gas exploration and production in this area.


2018 ◽  
Vol 63 (17) ◽  
pp. 175009
Author(s):  
Saeed M Al-Qahtani ◽  
Marie-Luise Wille ◽  
Christian M Langton

2020 ◽  
Vol 85 (4) ◽  
pp. 2001-2015
Author(s):  
Sophia Kronthaler ◽  
Jürgen Rahmer ◽  
Peter Börnert ◽  
Marcus R. Makowski ◽  
Benedikt J. Schwaiger ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Anastasopoulou ◽  
Dimitris Gorpas ◽  
Maximilian Koch ◽  
Evangelos Liapis ◽  
Sarah Glasl ◽  
...  

AbstractFluorescence imaging opens new possibilities for intraoperative guidance and early cancer detection, in particular when using agents that target specific disease features. Nevertheless, photon scattering in tissue degrades image quality and leads to ambiguity in fluorescence image interpretation and challenges clinical translation. We introduce the concept of capturing the spatially-dependent impulse response of an image and investigate Spatially Adaptive Impulse Response Correction (SAIRC), a method that is proposed for improving the accuracy and sensitivity achieved. Unlike classical methods that presume a homogeneous spatial distribution of optical properties in tissue, SAIRC explicitly measures the optical heterogeneity in tissues. This information allows, for the first time, the application of spatially-dependent deconvolution to correct the fluorescence images captured in relation to their modification by photon scatter. Using experimental measurements from phantoms and animals, we investigate the improvement in resolution and quantification over non-corrected images. We discuss how the proposed method is essential for maximizing the performance of fluorescence molecular imaging in the clinic.


1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.


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