Photoacoustic imaging of the human placental vasculature

Maneas, Efthymios; Aughwane, Rosalind; Huynh, Nam; Xia, Wenfeng; Ansari, Rehman; Singh, Mithun Kuniyil Ajith; Hutchinson, J. Ciaran; Sebire, Neil J.; Arthurs, Owen J.; Deprest, Jan; Ourselin, Sébastien; Beard, Paul C.; Melbourne, Andrew; Vercauteren, Tom; David, Anna L.; Desjardins, Adrien E.

doi:10.1002/jbio.201900167

Cited by 44 publications

(39 citation statements)

References 63 publications

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“…For PA follicle density evaluation, we used the 850 nm LED light source (longer wavelength, higher penetration depth). These maps are similar to previous studies that showed vascularity using PAI [ 47 , 48 , 49 ].…”

Section: Resultssupporting

confidence: 90%

Photoacoustic Imaging as a Tool for Assessing Hair Follicular Organization

Hariri

Moore

Mantri

et al. 2020

Sensors

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Follicular unit extraction (FUE) and follicular unit transplantation (FUT) account for 99% of hair transplant procedures. In both cases, it is important for clinicians to characterize follicle density for treatment planning and evaluation. The existing gold-standard is photographic examination. However, this approach is insensitive to subdermal hair and cannot identify follicle orientation. Here, we introduce a fast and non-invasive imaging technique to measure follicle density and angles across regions of varying density. We first showed that hair is a significant source of photoacoustic signal. We then selected regions of low, medium, and high follicle density and showed that photoacoustic imaging can measure the density of follicles even when they are not visible by eye. We performed handheld imaging by sweeping the transducer across the imaging area to generate 3D images via maximum intensity projection. Background signal from the dermis was removed using a skin tracing method. Measurement of follicle density using photoacoustic imaging was highly correlated with photographic determination (R2 = 0.96). Finally, we measured subdermal follicular angles—a key parameter influencing transection rates in FUE.

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Section: Resultssupporting

confidence: 90%

Photoacoustic Imaging as a Tool for Assessing Hair Follicular Organization

Hariri

Moore

Mantri

et al. 2020

Sensors

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“…A backward-mode FP interferometer (FPI) has also been developed to achieve high-resolution all-optical PAT, ( Figure 14 a) [ 145 , 146 , 147 ]. The FPI sensor head has a planar polymer (Parylene C) film spacer, which is sandwiched by two dichroic mirrors.…”

Section: All-optical Detection Reflection-mode Photoacoustic Micromentioning

confidence: 99%

“…When the thickness of the polymer is changed by the incident PA pressure, the reflectance intensity would be modulated, and thus the amplitude of PA signals can be detected. By using the FPI-based PAM system, researchers have demonstrated in vivo imaging for human palm vasculature [ 148 , 149 ], human peripheral limb arteries [ 150 ], mouse brain vasculature [ 146 ], and human placental vasculature [ 147 ]. Optical fiber-based FPIs have also been developed with high sensitivity, broadband, small footprint, and wide detection angels [ 151 , 152 , 153 ].…”

Section: All-optical Detection Reflection-mode Photoacoustic Micromentioning

confidence: 99%

A Review of Endogenous and Exogenous Contrast Agents Used in Photoacoustic Tomography with Different Sensing Configurations

Tsang

Wong

2020

Sensors

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Optical-based sensing approaches have long been an indispensable way to detect molecules in biological tissues for various biomedical research and applications. The advancement in optical microscopy is one of the main drivers for discoveries and innovations in both life science and biomedical imaging. However, the shallow imaging depth due to the use of ballistic photons fundamentally limits optical imaging approaches’ translational potential to a clinical setting. Photoacoustic (PA) tomography (PAT) is a rapidly growing hybrid imaging modality that is capable of acoustically detecting optical contrast. PAT uniquely enjoys high-resolution deep-tissue imaging owing to the utilization of diffused photons. The exploration of endogenous contrast agents and the development of exogenous contrast agents further improve the molecular specificity for PAT. PAT’s versatile design and non-invasive nature have proven its great potential as a biomedical imaging tool for a multitude of biomedical applications. In this review, representative endogenous and exogenous PA contrast agents will be introduced alongside common PAT system configurations, including the latest advances of all-optical acoustic sensing techniques.

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“…51 New methods such as photoacoustic imaging, which can be incorporated into current fetoscopes, can also be used to enhance the identification of placental vessels to improve success of ablation. 52 Thus, while we have seen advances in data collection to demonstrate likely maternal complication rates, more needs to be done in this area to help determine the optimal approaches, including longterm outcome studies. In addition, as we see new technologies being applied, we must ensure good, (randomised) prospective trials are performed to obtain objective evidence of the best approaches to use.…”

Section: Advances In Fetal Theraphymentioning

confidence: 99%

“…An early application is likely to be in the treatment of twin‐to‐twin transfusion syndrome where a combination of Doppler and MRI are used to determine placenta and vascular structure, and, using computer vision and deep learning techniques, the ideal entry point and the laser trajectory can be determined . New methods such as photoacoustic imaging, which can be incorporated into current fetoscopes, can also be used to enhance the identification of placental vessels to improve success of ablation …”

Section: Advances In Fetal Theraphymentioning

confidence: 99%