Evaluating the Combined Effect of a Choline Kinase Inhibitor and Temozolomide Therapy in a Mouse Model of Glioblastoma Using H MR Spectroscopy and IVIM-DWI.

This study evaluated the therapeutic efficacy of combining a choline kinase alpha (ChoKα) inhibitor, MN58b, and temozolomide (TMZ) in a syngeneic GL261 glioblastoma (GBM) mouse model. It used MR spectroscopy (MRS) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) to assess metabolic and microstructural changes within the tumor. Fifty-two C57BL/6 mice had GL261 cells implanted intracranially and were divided into four groups: saline control, MN58b, TMZ, and MN58b + TMZ (n = 16, 14, 11, and 11, respectively).

Pilot study on photoacoustic imaging and confocal Raman spectroscopy-derived biomarkers for assessing structural and physiological skin changes in atopic dermatitis and metabolic diseases.

Atopic dermatitis (AD), a chronic inflammatory condition, is closely associated with obesity and type 2 diabetes mellitus (diabetes/DM). For the first time, using high-resolution photoacoustic imaging (PAI) and in-house-developed handheld confocal Raman spectroscopy (CRS), we studied in 35 subjects the dermal microvascular architecture, epidermal biochemical profiles and skin alterations in AD with DM and obesity. Utilizing the imaging-derived markers, we observed pronounced dermal hypervascularization in DM and obesity, worsening with AD, as reflected by altered oxygen saturation and epidermal biochemicals.

Characterisation of equine odontoclastic tooth resorption and hypercementosis: A comparative study using microCT and radiography in age-matched controls.

Background: Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a painful disorder primarily affecting the incisor teeth of horses over 15 years of age. Clinical signs of the disease include prehension problems, halitosis and in severe cases weight loss. The disease predominately affects the reserve crown and presents as a loss of dental tissue and excessive build-up of cementum.

An Investigation of Signal Preprocessing for Photoacoustic Tomography.

Photoacoustic tomography (PAT) is increasingly being used for high-resolution biological imaging at depth. Signal-to-noise ratios and resolution are the main factors that determine image quality. Various reconstruction algorithms have been proposed and applied to reduce noise and enhance resolution, but the efficacy of signal preprocessing methods which also affect image quality, are seldom discussed.

Multispectral raster-scanning optoacoustic mesoscopy differentiate lesional from non-lesional atopic dermatitis skin using structural and functional imaging markers.

Atopic dermatitis (AD) is a chronic and pruritic skin inflammatory disease causing a significant burden to health care management and patient's quality of life. Seemingly healthy skin or non-lesional sites on AD patients still presents skin barrier defects and immune response, which can develop to AD at a later stage. To investigate further the balance between the epidermal barrier impairment and intrinsic immune dysregulation in AD, we exploited multispectral Raster-Scanning Optoacoustic Mesoscopy (ms-RSOM) to image lesional and non-lesional skin areas on AD patients of different severities non-invasively to elucidate their structural features and functional information.

Rapid and sensitive detection of ovarian cancer biomarker using a portable single peak Raman detection method.

Raman spectroscopy (RS) is a widely used non-destructive technique for biosensing applications because of its ability to detect unique 'fingerprint' spectra of biomolecules from the vibrational bands. To detect these weak fingerprint spectra, a complex detection system consisting of expensive detectors and optical components are needed. As a result, surface enhanced Raman spectroscopy (SERS) method were used to increase the Raman signal multifold beyond 10 times.

Machine Learning Assisted Handheld Confocal Raman Micro-Spectroscopy for Identification of Clinically Relevant Atopic Eczema Biomarkers.

Atopic dermatitis (AD) is a common chronic inflammatory skin dermatosis condition due to skin barrier dysfunction that causes itchy, red, swollen, and cracked skin. Currently, AD severity clinical scores are subjected to intra- and inter-observer differences. There is a need for an objective scoring method that is sensitive to skin barrier differences.

Biochemical "decoding" of breast ultrasound images with optoacoustic tomography fusion: First-in-human display of lipid and collagen signals on breast ultrasound.

To date, studies which utilized ultrasound (US) and optoacoustic tomography (OT) fusion (US-OT) in biochemical differentiation of malignant and benign breast conditions have relied on limited biochemical data such as oxyhaemoglobin (OH) and deoxyhaemoglobin (DH) only. There has been no data of the largest biochemical components of breast fibroglandular tissue: lipid and collagen. Here, the authors believe the ability to image collagen and lipids within the breast tissue could serve as an important milestone in breast US-OT imaging with many potential downstream clinical applications.

Microvascular imaging and monitoring of hemodynamic changes in the skin during arterial-venous occlusion using multispectral raster-scanning optoacoustic mesoscopy.

The ability to monitor oxygen delivery in microvasculature plays a vital role in measuring the viability of skin tissue and the probability of recovery. Using currently available clinical imaging tools, it is difficult to observe non-invasive hemodynamic regulation in the peripheral vessels. Here we propose the use of a novel multispectral raster-scanning optoacoustic mesoscopy (RSOM) system for noninvasive clinical monitoring of hemodynamic changes in the skin microvasculature's oxy- (HbO) and deoxy-hemoglobin (Hb), total hemoglobin (HbT) and oxygen saturation (rsO).

Biophotonic technologies for assessment of breast tumor surgical margins-A review.

Breast conserving surgery (BCS) offering similar surgical outcomes as mastectomy while retaining breast cosmesis is becoming increasingly popular for the management of early stage breast cancers. However, its association with reoperation rates of 20% to 40% following incomplete tumor removal warrants the need for a fast and accurate intraoperative surgical margin assessment tool that offers cellular, structural and molecular information of the whole specimen surface to a clinically relevant depth. Biophotonic technologies are evolving to qualify as such an intraoperative tool for clinical assessment of breast cancer surgical margins at the microscopic and macroscopic scale.

Optoacoustic characterization of breast conserving surgery specimens - A pilot study.

In this pilot study, we tested an ultrasound-guided optoacoustic tomography (US-OT) two-dimensional (2D) array scanner to understand the optoacoustic patterns of excised breastconserving surgery (BCS) specimens. We imaged 14 BCS specimens containing malignant tumors at eight wavelengths spanning 700-1100 nm. Spectral unmixing across multiple wavelengths allowed for visualizing major intrinsic chromophores in the breast tissue including hemoglobin and lipid up to a depth of 7 mm.

Handheld confocal Raman spectroscopy (CRS) for objective assessment of skin barrier function and stratification of severity in atopic dermatitis (AD) patients.

Background: We developed the first-of-its-kind handheld confocal Raman spectroscopy (CRS) system to quantify the concentration of natural moisturizing factors in the skin.

Objective: To evaluate the feasibility of our handheld CRS system and propose a novel quantitative index to measure skin barrier function.

Methods: This prospective study included 30 atopic dermatitis (AD) patients and 14 healthy volunteers.

A review of clinical photoacoustic imaging: Current and future trends.

Photoacoustic imaging (or optoacoustic imaging) is an upcoming biomedical imaging modality availing the benefits of optical resolution and acoustic depth of penetration. With its capacity to offer structural, functional, molecular and kinetic information making use of either endogenous contrast agents like hemoglobin, lipid, melanin and water or a variety of exogenous contrast agents or both, PAI has demonstrated promising potential in a wide range of preclinical and clinical applications. This review provides an overview of the rapidly expanding clinical applications of photoacoustic imaging including breast imaging, dermatologic imaging, vascular imaging, carotid artery imaging, musculoskeletal imaging, gastrointestinal imaging and adipose tissue imaging and the future directives utilizing different configurations of photoacoustic imaging.

Ultrasound Guided Optoacoustic Tomography in Assessment of Tumor Margins for Lumpectomies.

Purpose: To determine the accuracy of a handheld ultrasound-guided optoacoustic tomography (US-OT) probe developed for human deep-tissue imaging in ex vivo assessment of tumor margins postlumpectomy.

Methods: A custom-built two-dimensional (2D) US-OT-handheld probe was used to scan 15 lumpectomy breast specimens. Optoacoustic signals acquired at multiple wavelengths between 700 and 1100 nm were reconstructed using model linear algorithm, followed by spectral unmixing for lipid and deoxyhemoglobin (Hb).

Acoustic resolution photoacoustic microscopy based on microelectromechanical systems scanner.

Photoacoustic microscopy (PAM) can be classified as optical resolution (OR)-PAM and acoustic resolution (AR)-PAM depending on the type of resolution achieved. Using microelectromechanical systems (MEMS) scanner, high-speed OR-PAM system was developed earlier. Depth of imaging limits the use of OR-PAM technology for many preclinical and clinical imaging applications.

High-speed simultaneous multiscale photoacoustic microscopy.

Photoacoustic microscopy (PAM) is a fast-growing biomedical imaging technique that provides high-resolution in vivo imaging beyond the optical diffusion limit. Depending on the scalable lateral resolution and achievable penetration depth, PAM can be classified into optical resolution PAM (OR-PAM) and acoustic resolution PAM (AR-PAM). The use of a microelectromechanical systems (MEMS) scanner has improved OR-PAM imaging speed significantly and is highly beneficial in the development of miniaturized handheld devices.

In vivo label-free functional photoacoustic monitoring of ischemic reperfusion.

Pressure ulcer formation is a common problem among patients confined to bed or restricted to wheelchairs. The ulcer forms when the affected skin and underlying tissues go through repeated cycles of ischemia and reperfusion, leading to inflammation. This theory is evident by intravital imaging studies performed in immune cell-specific, fluorescent reporter mouse skin with induced ischemia-reperfusion (I-R) injuries.

Photoacoustic imaging of lamina cribrosa microcapillaries in porcine eyes.

Due to the embedded nature of the lamina cribrosa (LC) microcapillary network, conventional imaging techniques have failed to obtain the high-resolution images needed to assess the perfusion state of the LC. In this study, both optical resolution (OR) and acoustic resolution (AR) photoacoustic microscopy (PAM) techniques were used to obtain static and dynamic information about LC perfusion in ex vivo porcine eyes. The OR-PAM system could resolve a perfused LC microcapillary network with a lateral resolution of 4.

Optical resolution photoacoustic microscopy based on multimode fibers.

Photoacoustic microscopy (PAM) is a multiscale imaging technique. In optical-resolution photoacoustic microscopy (OR-PAM), a single mode (SM) fiber is normally used as the source of optical excitation to be focused into a diffraction-limited spot. Recent advances in OR-PAM have improved its imaging speed using microelectromechanical systems (MEMS).

Photoacoustic microscopy for evaluating combretastatin A4 phosphate induced vascular disruption in orthotopic glioma.

The use of an optical resolution photoacoustic microscopy (OR-PAM) system to evaluate the vascular disruptive effect of combretastatin A4 Phosphate (CA4P) on a murine orthotopic glioma with intact skull is described here. Second generation optical-resolution photoacoustic microscopy scanner with a 532 nm pulsed diode-pumped solid-state laser that specifically matches the absorption maximum of hemoglobin in tissues was used to image orthotopic glioma inoculated in mouse brain. Two-dimensional maps of brain vasculature with a lateral resolution of 5 μm and a depth of 700 μm at a field of view 5 × 4 mm were acquired on normal brain and glioma brain.

studies of transdermal nanoparticle delivery with microneedles using photoacoustic microscopy.

Microneedle technology allows micron-sized conduits to be formed within the outermost skin layers for both localized and systemic delivery of therapeutics including nanoparticles. Histological methods are often employed for characterization, and unfortunately do not allow for the visualization of the delivery process. This study presents the utilization of optical resolution-photoacoustic microscopy to characterize the transdermal delivery of nanoparticles using microneedles.

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging.

Photoacoustic microscopy (PAM) is a fast-growing invivo imaging modality that combines both optics and ultrasound, providing penetration beyond the optical mean free path (~1 mm in skin) with high resolution. By combining optical absorption contrast with the high spatial resolution of ultrasound in a single modality, this technique can penetrate deep tissues. Photoacoustic microscopy systems can have either a low acoustic resolution and probe deeply or a high optical resolution and probe shallowly.

Application of phase shifting electronic speckle pattern interferometry in studies of photoinduced shrinkage of photopolymer layers.

Photoinduced shrinkage occurring in photopolymer layers during holographic recording was determined by phase shifting electronic speckle pattern interferometry. Phase maps were calculated from the changes in intensity at each pixel due to the phase differences introduced between object and reference beams. Shrinkage was then obtained from the changes in phase as recording proceeded.