Multi-wavelength time-resolved optical mammography

A time-resolved optical mammograph operating at 7 wavelengths (637, 683, 785, 832, 905, 916, and 975 nm) in compressed breast geometry was developed. Its clinical application was started on patients bearing malignant and benign lesions. Late gated intensity images are used to obtain information on the spatial distribution of the absorption properties of breast. Scattering images derived from the diffusion theory are also applied for lesion detection and characterization. Cancers are identified in intensity images at short wavelengths, due to the high blood content, while cysts are typically characterized by low scattering at all wavelengths. The increase (from 4 to 7) in the number of wavelengths as compared to the previous versions of the instrument aims at improving the robustness of the fitting procedures for a better estimate of tissue composition and structure and of physiological parameters. Moreover, the new wavelengths contribute to the qualitatively identify tissue composition from intensity images, and could assist lesion detection.

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Bulk hemoglobin, lipid and water content in the female breast from multi-wavelength time-resolved optical mammography

Biomedical Topical Meeting ◽

10.1364/bio.2004.thb5 ◽

2004 ◽

Author(s):

Lorenzo Spinelli ◽

Alessandro Torricelli ◽

Antonio Pifferi ◽

Paola Taroni ◽

Rinaldo Cubeddu ◽

...

Keyword(s):

Water Content ◽

Time Resolved ◽

Optical Mammography ◽

Female Breast ◽

Multi Wavelength

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Characterization of female breast lesions from multi-wavelength time-resolved optical mammography

Physics in Medicine and Biology ◽

10.1088/0031-9155/50/11/004 ◽

2005 ◽

Vol 50 (11) ◽

pp. 2489-2502 ◽

Cited By ~ 68

Author(s):

Lorenzo Spinelli ◽

Alessandro Torricelli ◽

Antonio Pifferi ◽

Paola Taroni ◽

Gianmaria Danesini ◽

...

Keyword(s):

Breast Lesions ◽

Time Resolved ◽

Optical Mammography ◽

Female Breast ◽

Multi Wavelength

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Six-year source apportionment of submicron organic aerosols from near-continuous measurements at SIRTA (Paris area, France)

10.5194/acp-2019-515 ◽

2019 ◽

Author(s):

Yunjiang Zhang ◽

Olivier Favez ◽

Jean-Eudes Petit ◽

Francesco Canonaco ◽

Francois Truong ◽

...

Keyword(s):

Source Apportionment ◽

Biomass Burning ◽

Ambient Air ◽

Carbonaceous Aerosols ◽

Time Resolved ◽

Pronounced Increase ◽

Paris Area ◽

Multi Wavelength ◽

High Concentrations

Abstract. Organic aerosol (OA) particles are recognized as key factors influencing air quality and climate change. However, highly-time resolved year-round characterizations of their composition and sources in ambient air are still very limited due to challenging continuous observations. Here, we present an analysis of long-term variability of submicron OA using the combination of Aerosol Chemical Speciation Monitor (ACSM) and multi-wavelength aethalometer from November 2011 to March 2018 at a background site of the Paris region (France). Source apportionment of OA was achieved via partially constrained positive matrix factorization (PMF) using the multilinear engine (ME-2). Two primary OA (POA) and two oxygenated OA (OOA) factors were identified and quantified over the entire studied period. POA factors were designated as hydrocarbon-like OA (HOA) and biomass burning OA (BBOA). The latter factor presented a significant seasonality with higher concentrations in winter with significant monthly contributions to OA (18–33 %) due to enhanced residential wood burning emissions. HOA mainly originated from traffic emissions but was also influenced by biomass burning in cold periods. OOA factors were distinguished between their less- and more-oxidized fractions (LO-OOA and MO-OOA, respectively). These factors presented distinct seasonal patterns, associated with different atmospheric formation pathways. A pronounced increase of LO-OOA concentrations and contributions (50–66 %) was observed in summer, which may be mainly explained by secondary OA (SOA) formation processes involving biogenic gaseous precursors. Conversely high concentrations and OA contributions (32–62 %) of MO-OOA during winter and spring seasons were partly associated with anthropogenic emissions and/or long-range transport from northeastern Europe. The contribution of the different OA factors as a function of OA mass loading highlighted the dominant roles of POA during pollution episodes in fall and winter, and of SOA for highest springtime and summertime OA concentrations. Finally, long-term trend analyses indicated a decreasing feature (of about 200 ng m−3 yr−1) for MO-OOA, very limited or insignificant decreasing trends for primary anthropogenic carbonaceous aerosols (BBOA and HOA, along with the fossil fuel and biomass burning black carbon components), and no trend for LO-OOA over the 6+-year investigated period.

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