Spectral analysis assisted photoacoustic imaging for lipid composition differentiation

Cao, Yanguang; Kole, Ayeeshik; Lan, Lu; Wang, Pu; Hui, Jie; Sturek, Michael; Cheng, Ji

doi:10.1016/j.pacs.2017.05.002

Cited by 29 publications

(24 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This gives the gene a critical role in lipid accumulation within LC-HLDs. And supports the strong association of promoter region polymorphism in apolipoprotein C3 (APOC3) (rs2854117 [− 482C>T] and rs2854116 [− 455T > C]) found to be strongly associated with NAFLD and its associated diseases, hypertriglyceridemia, metabolic syndrome, and coronary artery disease [45][46][47][48]. Thus, polymorphisms in the APOC3 gene resulting in greater than normal incorporation of cholesteric lipids into LC-HLDs would put the individual at greater risk of over saturating the HLDs liquid crystal buffering system and transitioning the HLD into its damaging crystalline form.…”

Section: Discussionsupporting

confidence: 55%

Nonalcoholic fatty liver disease experiences accumulation of hepatic liquid crystal associated with increasing lipophagy

Wang

Jones

et al. 2020

Cell Biosci

View full text Add to dashboard Cite

Background: In the past 30 years, incidences of non-alcoholic fatty liver disease (NAFLD) has risen by 30%. However, there is still no clear mechanism or accurate method of anticipating liver failure. Here we reveal the phase transitions of liquid crystalline qualities in hepatic lipid droplets (HLDs) as a novel method of anticipating prognosis. Methods: NAFLD was induced by feeding C57BL/6J mice on a high-fat (HiF) diet. These NAFLD livers were then evaluated under polarized microscopy, X-ray diffraction and small-angle scattering, lipid component chromatography analysis and protein expression analysis. Optically active HLDs from mouse model and patient samples were both then confirmed to have liquid crystal characteristics. Liver MAP1LC3A expression was then evaluated to determine the role of autophagy in liquid crystal HLD (LC-HLD) formation. Results: Unlike the normal diet cohort, HiF diet mice developed NAFLD livers containing HLDs exhibiting Maltese cross birefringence, phase transition, and fluidity signature to liquid crystals. These LC-HLDs transitioned to anisotropic crystal at 0 °C and remain crystalline. Temperature increase to 42 °C causes both liquid crystal and crystal HLDs to convert to isotropic droplet form. These isotropic HLDs successfully transition to anisotropic LC with fast temperature decrease and anisotropic crystal with slow temperature decrease. These findings were duplicated in patient liver. Patient LC-HLDs with no inner optical activity were discovered, hinting at lipid saturation as the mechanism through which HLD acquire LC characteristics. Downregulation of MAP1LC3A in conjunction with increased LC-HLD also implicated autophagy in NAFLD LC-HLD formation. Conclusions: Increasing concentrations of amphiphilic lipids in HLDs favors organization into alternating hydrophilic and hydrophobic layers, which present as LC-HLDs. Thus, evaluating the extent of liquid crystallization with phase transition in HLDs of NAFLD patients may reveal disease severity and predict impending liver damage.

show abstract

Section: Discussionsupporting

confidence: 55%

Nonalcoholic fatty liver disease experiences accumulation of hepatic liquid crystal associated with increasing lipophagy

Wang

Jones

et al. 2020

Cell Biosci

View full text Add to dashboard Cite

show abstract

“…Existing TMMs that are widely used for optical and ultrasound phantoms have limitations for photoacoustic imaging. Aqueous phantoms such as those based on agar [ 4 ] and gelatin [ 5 ] are often useful, since constituents to modify optical and acoustic properties are well known [ 6 – 8 ]. However, they tend to have limited mechanical strength and high evaporation rates.…”

Section: Introductionmentioning

confidence: 99%

Gel wax-based tissue-mimicking phantoms for multispectral photoacoustic imaging

Maneas

Xia

Ogunlade

et al. 2018

Biomed. Opt. Express

View full text Add to dashboard Cite

Tissue-mimicking phantoms are widely used for the calibration, evaluation and standardisation of medical imaging systems, and for clinical training. For photoacoustic imaging, tissue-mimicking materials (TMMs) that have tuneable optical and acoustic properties, high stability, and mechanical robustness are highly desired. In this study, gel wax is introduced as a TMM that satisfies these criteria for developing photoacoustic imaging phantoms. The reduced scattering and optical absorption coefficients were independently tuned with the addition of TiO2 and oil-based inks. The frequency-dependent acoustic attenuation obeyed a power law; for native gel wax, it varied from 0.71 dB/cm at 3 MHz to 9.93 dB/cm at 12 MHz. The chosen oil-based inks, which have different optical absorption spectra in the range of 400 to 900 nm, were found to have good photostability under pulsed illumination with photoacoustic excitation light. Optically heterogeneous phantoms that comprised of inclusions with different concentrations of carbon black and coloured inks were fabricated, and multispectral photoacoustic imaging was performed with an optical parametric oscillator and a planar Fabry-Pérot sensor. We conclude that gel wax is well suited as a TMM for multispectral photoacoustic imaging.

show abstract

“…We intend to build a larger calibration data set to address this limitation. In addition, we anticipate future application of spectral algorithms to differentiate between cholesterol subtypes, as a surrogate marker of inflammation [39].…”

Section: Discussionmentioning

confidence: 99%

Comparative Quantification of Arterial Lipid by Intravascular Photoacoustic-Ultrasound Imaging and Near-Infrared Spectroscopy-Intravascular Ultrasound

Kole

Cao

Hui

et al. 2018

J. of Cardiovasc. Trans. Res.

Self Cite

View full text Add to dashboard Cite

Intravascular photoacoustic-ultrasound (IVPA-US) imaging and near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) are two hybrid modalities that detect arterial lipid, with comparison necessary to understand the relative advantages of each. We performed in vivo and ex vivo IVPA-US imaging of the iliac arteries of Ossabaw swine with metabolic syndrome (MetS) and lean swine to investigate sensitivity for early-stage atherosclerosis. We repeated imaging ex vivo with NIRS-IVUS for comparison to IVPA-US and histology. Both modalities showed significantly greater lipid in MetS vs. lean swine, but only IVPA-US localized the lipid as perivascular. To investigate late-stage atherosclerosis, we performed ex vivo IVPA-US imaging of a human coronary artery with comparison to NIRS-IVUS and histology. Two advanced fibroatheromas were identified, with agreement between IVPA-measured lipid area and NIRS-derived lipid content. As confirmed histologically, IVPA-US has sensitivity to detect lipid content similar to NIRS-IVUS and provides additional depth resolution, enabling quantification and localization of lipid cores within plaques. Electronic supplementary material The online version of this article (10.1007/s12265-018-9849-2) contains supplementary material, which is available to authorized users.

show abstract

Spectral analysis assisted photoacoustic imaging for lipid composition differentiation

Cited by 29 publications

References 35 publications

Nonalcoholic fatty liver disease experiences accumulation of hepatic liquid crystal associated with increasing lipophagy

Nonalcoholic fatty liver disease experiences accumulation of hepatic liquid crystal associated with increasing lipophagy

Gel wax-based tissue-mimicking phantoms for multispectral photoacoustic imaging

Comparative Quantification of Arterial Lipid by Intravascular Photoacoustic-Ultrasound Imaging and Near-Infrared Spectroscopy-Intravascular Ultrasound

Contact Info

Product

Resources

About