scholarly journals Ultrasound-Guided Detection and Segmentation of Photoacoustic Signals from Bone Tissue In Vivo

2020 ◽  
Vol 11 (1) ◽  
pp. 19
Author(s):  
Ting Feng ◽  
Yunhao Zhu ◽  
Chengcheng Liu ◽  
Sidan Du ◽  
Dean Ta ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Bone Tissue ◽  
Bone Health ◽  
Spatial Information ◽  
Health Assessment ◽  
Biological Tissues ◽  
Ultrasound Guided ◽  
Non Invasive ◽  
In Vivo Experiment

Photoacoustic (PA) techniques provide optical absorption contrast and spatial information at an ultrasound resolution in deep biological tissues. Among the greatest challenges encountered in the PA examination of bone is the analysis of trabecular bone, which holds key chemical and physical information required for bone health assessments. Ultrasound detection is naturally registered with PA detection; therefore, in this study, we propose ultrasound guidance for the PA detection of trabecular bone. We perform both numerical simulations and an in vivo experiment on a human subject to investigate the possibility of ultrasound-guided detection and segmentation of photoacoustic signals from bone tissue in vivo in a non-invasive manner. The results obtained from the simulation and in vivo experiment suggest that the ultrasound-guided PA method can distinguish PA signals from trabecular and cortical bones as well as from the overlying soft tissue. Considering that the PA technique is non-ionizing and non-invasive, it holds potential for clinical bone health assessment.

scholarly journals A Robust Method for Adjustment of Laser Speckle Contrast Imaging during Transcranial Mouse Brain Visualization

Photonics ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 80 ◽  
Author(s):  
Vyacheslav Kalchenko ◽  
Anton Sdobnov ◽  
Igor Meglinski ◽  
Yuri Kuznetsov ◽  
Guillaume Molodij ◽  
...  
Keyword(s):  
Biological Tissues ◽  
Laser Speckle ◽  
Robust Method ◽  
Scattering Media ◽  
Contrast Imaging ◽  
Speckle Contrast ◽  
Non Invasive ◽  
Sagittal Sinus ◽  
Brain Vasculature

Laser speckle imaging (LSI) is a well-known and useful approach for the non-invasive visualization of flows and microcirculation localized in turbid scattering media, including biological tissues (such as brain vasculature, skin capillaries etc.). Despite an extensive use of LSI for brain imaging, the LSI technique has several critical limitations. One of them is associated with inability to resolve a functionality of vessels. This limitation also leads to the systematic error in the quantitative interpretation of values of speckle contrast obtained for different vessel types, such as sagittal sinus, arteries, and veins. Here, utilizing a combined use of LSI and fluorescent intravital microscopy (FIM), we present a simple and robust method to overcome the limitations mentioned above for the LSI approach. The proposed technique provides more relevant, abundant, and valuable information regarding perfusion rate ration between different types of vessels that makes this method highly useful for in vivo brain surgical operations.

scholarly journals Non-invasive airway health assessment: Synchrotron imaging reveals effects of rehydrating treatments on mucociliary transit in-vivo

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Martin Donnelley ◽  
Kaye S. Morgan ◽  
Karen K. W. Siu ◽  
Nigel R. Farrow ◽  
Charlene S. Stahr ◽  
...  
Keyword(s):  
Health Assessment ◽  
Non Invasive ◽  
Synchrotron Imaging

Bone density, microarchitecture and tissue quality after 1 year of treatment with dolutegravir/abacavir/lamivudine

2020 ◽  
Vol 75 (10) ◽  
pp. 2998-3003
Author(s):  
Jade Soldado-Folgado ◽  
Elisabeth Lerma-Chippirraz ◽  
Itziar Arrieta-Aldea ◽  
Daniel Bujosa ◽  
Natalia García-Giralt ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Bone Tissue ◽  
Bone Quality ◽  
Bone Health ◽  
Trabecular Bone Score ◽  
Bone Microarchitecture ◽  
Tissue Quality ◽  
Art Initiation ◽  
The Impact ◽  
Health Parameters

Abstract Background Bone mineral density (BMD) decreases with ART initiation with a tenofovir disoproxil fumarate-containing regimen, although bone tissue quality increases. The impact of dolutegravir (DTG)/abacavir (ABC)/lamivudine (3TC)-based ART initiation on bone health parameters is not clear. Objectives To study the impact of DTG/ABC/3TC-based therapy on bone health parameters in ART-naive individuals with HIV after 48 weeks of treatment. Methods An observational, prospective and analytical study of treatment-naive patients with HIV undergoing a DTG/ABC/3TC-based regimen at 48 week follow-up. Changes in bone strength parameters (BMD, bone microarchitecture and bone tissue quality) were assessed with non-parametric methods. Results Sixteen HIV-infected ART-naive patients starting DTG/ABC/3TC were included. BMD in the lumbar spine showed a significant decrease of −2.25% (P = 0.007) and −4.1% in the femoral neck (P = 0.007). Bone microarchitecture, as measured by trabecular bone score, also decreased significantly by −2.5% (P = 0.03). In contrast, bone quality [bone material strength index (BMi)], as measured by microindentation, significantly increased with respect to baseline after 48 weeks of treatment, showing better bone properties of +6.53% (P < 0.001). No significant changes were found in bone turnover markers. In addition, a positive significant correlation between the CD4/CD8 cell count ratio at baseline and changes in BMSi after 48 weeks of treatment was observed (Spearman’s rho = 0.4974; P = 0.04). Conclusions After a 48 week treatment with DTG/ABC/3TC-based ART, BMD and trabecular bone score decreased while bone tissue quality, as measured by microindentation, improved significantly. The state of the immune system at ART initiation is related to bone quality recovery. An overarching approach to assess bone toxicity in ART-treated patients is needed.

scholarly journals Detection of Age-Related Changes in Tendon Molecular Composition by Raman Spectroscopy—Potential for Rapid, Non-Invasive Assessment of Susceptibility to Injury

2020 ◽  
Vol 21 (6) ◽  
pp. 2150
Author(s):  
Nai-Hao Yin ◽  
Anthony W. Parker ◽  
Pavel Matousek ◽  
Helen L. Birch
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Flexor Tendon ◽  
Biological Tissues ◽  
Ring Structure ◽  
Total N ◽  
Non Invasive ◽  
Age Related ◽  
Superficial Digital Flexor Tendon

The lack of clinical detection tools at the molecular level hinders our progression in preventing age-related tendon pathologies. Raman spectroscopy can rapidly and non-invasively detect tissue molecular compositions and has great potential for in vivo applications. In biological tissues, a highly fluorescent background masks the Raman spectral features and is usually removed during data processing, but including this background could help age differentiation since fluorescence level in tendons increases with age. Therefore, we conducted a stepwise analysis of fluorescence and Raman combined spectra for better understanding of the chemical differences between young and old tendons. Spectra were collected from random locations of vacuum-dried young and old equine tendon samples (superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT), total n = 15) under identical instrumental settings. The fluorescence-Raman spectra showed an increase in old tendons as expected. Normalising the fluorescence-Raman spectra further indicated a potential change in intra-tendinous fluorophores as tendon ages. After fluorescence removal, the pure Raman spectra demonstrated between-group differences in CH2 bending (1450 cm−1) and various ring-structure and carbohydrate-associated bands (1000–1100 cm−1), possibly relating to a decline in cellular numbers and an accumulation of advanced glycation end products in old tendons. These results demonstrated that Raman spectroscopy can successfully detect age-related tendon molecular differences.

scholarly journals Erratum: CORRIGENDUM: Non-invasive airway health assessment: Synchrotron imaging reveals effects of rehydrating treatments on mucociliary transit in-vivo

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Martin Donnelley ◽  
Kaye S. Morgan ◽  
Karen K. W. Siu ◽  
Nigel R. Farrow ◽  
Charlene S. Stahr ◽  
...  
Keyword(s):  
Health Assessment ◽  
Non Invasive ◽  
Synchrotron Imaging

scholarly journals Non-invasive chemically specific measurement of subsurface temperature in biological tissues using surface-enhanced spatially offset Raman spectroscopy

2016 ◽  
Vol 187 ◽  
pp. 329-339 ◽  
Author(s):  
Benjamin Gardner ◽  
Nicholas Stone ◽  
Pavel Matousek
Keyword(s):  
Raman Spectroscopy ◽  
High Sensitivity ◽  
Biological Tissues ◽  
Temperature Monitoring ◽  
Subsurface Temperature ◽  
Non Invasive ◽  
Wide Range ◽  
Subsurface Monitoring ◽  
Mean Square Errors

Here we demonstrate for the first time the viability of characterising non-invasively the subsurface temperature of SERS nanoparticles embedded within biological tissues using spatially offset Raman spectroscopy (SORS). The proposed analytical method (T-SESORS) is applicable in general to diffusely scattering (turbid) media and features high sensitivity and high chemical selectivity. The method relies on monitoring the Stokes and anti-Stokes bands of SERS nanoparticles in depth using SORS. The approach has been conceptually demonstrated using a SORS variant, transmission Raman spectroscopy (TRS), by measuring subsurface temperatures within a slab of porcine tissue (5 mm thick). Root-mean-square errors (RMSEs) of 0.20 °C were achieved when measuring temperatures over ranges between 25 and 44 °C. This unique capability complements the array of existing, predominantly surface-based, temperature monitoring techniques. It expands on a previously demonstrated SORS temperature monitoring capability by adding extra sensitivity stemming from SERS to low concentration analytes. The technique paves the way for a wide range of applications including subsurface, chemical-specific, non-invasive temperature analysis within turbid translucent media including: the human body, subsurface monitoring of chemical (e.g. catalytic) processes in manufacture quality and process control and research. Additionally, the method opens prospects for control of thermal treatment of cancer in vivo with direct non-invasive feedback on the temperature of mediating plasmonic nanoparticles.

scholarly journals SPETTROSCOPIA E IMAGING IN OTTICA DIFFUSA: FOCUS SUL TUMORE DELLA MAMMELLA

2020 ◽  
Author(s):  
Paola Taroni
Keyword(s):  
Breast Cancer ◽  
Near Infrared ◽  
Breast Cancer Diagnosis ◽  
Biological Tissues ◽  
Blood Parameters ◽  
Collagen Content ◽  
Diffuse Optics ◽  
Non Invasive ◽  
Ultrasound Diagnostics

Through the measurement of the optical properties (absorption and scattering), diffuse optical spectroscopy allows one to estimate non-invasively the composition of biological tissues (water, lipid and collagen content) and functional blood parameters. Further, it provides information on the microscopic tissue structure. It can therefore be effectively used in vivo as an absolutely non-invasive diagnostic tool. The Department of Physics of the Politecnico di Milano has designed and built an optical mammograph that exploits diffused optics, operating with pulsed light at 7 wavelengths in the red and near infrared spectral range (635-1060 nm). The instrument was used in a clinical study on 200 subjects, in collaboration with the European Institute of Oncology: optically derived tissue composition and in particular collagen content in tissues proved to be effective both to discriminate between malignant and benign breast lesions, and to estimate the risk of breast cancer related to the density of breast tissue, which is recognized among the most important independent risk factors. Partly based on those results, “SOLUS - Smart optical and ultrasound diagnostics of breast cancer”, a European project in the H2020 Framework Program, is now working to improve the specificity of non-invasive breast cancer diagnosis by combining diffuse optics with ultrasound imaging.

scholarly journals Non-invasive depth determination of inclusion in biological tissues using spatially offset Raman spectroscopy with external calibration

The Analyst ◽  
2020 ◽  
Vol 145 (23) ◽  
pp. 7623-7629 ◽  
Author(s):  
Sara Mosca ◽  
Priyanka Dey ◽  
Marzieh Salimi ◽  
Francesca Palombo ◽  
Nick Stone ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Biological Tissues ◽  
Disease Diagnosis ◽  
Early Disease ◽  
External Calibration ◽  
Non Invasive ◽  
Depth Determination

Spatially Offset Raman Spectroscopy (SORS) allows chemical characterisation of biological tissues at depths enabling in vivo localization of biomarkers for early disease diagnosis.

scholarly journals Nuclear magnetic resonance: actualities and perspectives

Medic ro ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 29-34
Author(s):  
Micu Maria-Andreea ◽  
Emese Orban
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Physical Process ◽  
Biological Tissues ◽  
Medical Setting ◽  
Non Invasive ◽  
Surgical Field ◽  
Nuclear Magnetic

Nuclear magnetic resonance (NMR) is a complex physical process based on the interaction of protons in an electro­mag­ne­tic field, the most well-known and widespread ap­pli­cation in medical-clinical and medical-surgical field being nuclear magnetic resonance imaging. Considering the interdependent relationship between research in scien­ti­fic fields that are closely related to medicine and the me­di­cal world, it is particularly important to be aware of the existence of other applications of the physical process men­tioned before: diffusionometry, relaxometry and MRI spectroscopy. These are well-known and studied research entities, but their applicability in the clinical diagnostic pro­cess is still limited, despite the huge potential to provide a much broader and more detailed perspective on various biological tissues in vitro, but even in vivo. We want to re­view the evolution of nuclear magnetic resonance to­mo­gra­phy or imaging, which has gone from being a Nobel Prize-winning idea to one of the most widespread and useful methods of non-invasive and non-irradiating me­di­cal imaging, but especially an example of the feasi­bi­li­ty of diffusionometry, relaxometry, respectively MRI spec­tro­scopy in a medical setting, through global studies on their po­ten­tial diagnosis in areas such as oncology, neurology, en­do­cri­no­logy and others.  

scholarly journals Fast holographic scattering compensation for deep tissue biological imaging

2021 ◽  
Author(s):  
Molly A. May ◽  
Nicolas Barré ◽  
Kai Kummer ◽  
Micheala Kress ◽  
Monika Ritsch-Marte ◽  
...  
Keyword(s):  
Single Point ◽  
Biological Tissues ◽  
Rapid Improvement ◽  
Major Barrier ◽  
Non Invasive ◽  
Phase Stepping ◽  
Order Of Magnitude ◽  
Previous State ◽  
Two Photon Fluorescence

Scattering in biological tissues is a major barrier for in vivo optical imaging of all but the most superficial structures. Progress toward overcoming the distortions caused by scattering in turbid media has been made by shaping the excitation wavefront to redirect power into a single point in the imaging plane. However, fast, non-invasive determination of the required wavefront compensation remains challenging. Here, we introduce a quickly converging algorithm for non-invasive scattering compensation, termed DASH, in which holographic phase stepping interferometry enables new phase information to be updated after each measurement. This leads to rapid improvement of the wavefront correction, forming a focus after just one measurement iteration and achieving an order of magnitude higher signal enhancement at this stage than the previous state-of-the-art. Using DASH, we demonstrate two-photon fluorescence imaging of microglia cells in highly turbid mouse hippocampal tissue down to a depth of 530 μm.

Sign in / Sign up

Export Citation Format

Share Document