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Sijilmassi O, López Alonso JM, Del Río Sevilla A, Barrio Asensio MDC. Multispectral Imaging Method for Rapid Identification and Analysis of Paraffin-Embedded Pathological Tissues. J Digit Imaging 2023; 36:1663-1674. [PMID: 37072579 PMCID: PMC10406798 DOI: 10.1007/s10278-023-00826-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/20/2023] Open
Abstract
The study of the interaction between light and biological tissue is of great help in the identification of diseases as well as structural alterations in tissues. In the present study, we have developed a tissue diagnostic technique by using multispectral imaging in the visible spectrum combined with principal component analysis (PCA). We used information from the propagation of light through paraffin-embedded tissues to assess differences in the eye tissues of control mouse embryos compared to mouse embryos whose mothers were deprived of folic acid (FA), a crucial vitamin necessary for the growth and development of the fetus. After acquiring the endmembers from the multispectral images, spectral unmixing was used to identify the abundances of those endmembers in each pixel. For each acquired image, the final analysis was performed by performing a pixel-by-pixel and wavelength-by-wavelength absorbance calculation. Non-negative least squares (NNLS) were used in this research. The abundance maps obtained for the first endmember revealed vascular alterations (vitreous and choroid) in the embryos with maternal FA deficiency. However, the abundance maps obtained for the third endmember showed alterations in the texture of some tissues such as the lens and retina. Results indicated that multispectral imaging applied to paraffin-embedded tissues enhanced tissue visualization. Using this method, first, it can be seen tissue damage location and then decide what kind of biological techniques to apply.
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Affiliation(s)
- Ouafa Sijilmassi
- Faculty of Optics and Optometry, Anatomy and Embryology Department, Universidad Complutense de Madrid, Madrid, Spain.
- Optics Department, Faculty of Optics and Optometry, Universidad Complutense De Madrid, Madrid, Spain.
| | - José-Manuel López Alonso
- Optics Department, Faculty of Optics and Optometry, Universidad Complutense De Madrid, Madrid, Spain
| | - Aurora Del Río Sevilla
- Faculty of Optics and Optometry, Anatomy and Embryology Department, Universidad Complutense de Madrid, Madrid, Spain
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Abstract
PURPOSE Knowledge of how blood perfusion is affected during and after reconstructive surgery is of great importance to predict the survival of grafts and flaps. When commonly used reconstructive procedures were developed a century ago, they were based on empirical observations of clinical outcome. METHODS This is a comprehensive literature review that summarizes the current state of knowledge regarding microvascular perfusion monitoring during oculoplastic procedures. RESULTS Over the years, a number of techniques for perfusion monitoring have been developed as an attempt to be more objective than clinical examination using traditional methods such as observations of skin temperature, turgor, color, smell, and capillary refill time. There are limited publications regarding microvascular perfusion monitoring during reconstructive procedures in the periocular area. Modern laser-based techniques have been attractive due to their noninvasive nature. CONCLUSIONS Today, modern, noninvasive techniques are available to monitor perfusion during and after surgery. This has increased our knowledge on the perfusion in common oculoplastic surgery procedures. A detailed understanding of how blood perfusion is affected will hopefully allow the improvement of surgical techniques for better clinical outcome.
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Affiliation(s)
- Johanna V Berggren
- Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Ophthalmology, Lund, Sweden
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Bunke J, Merdasa A, Stridh M, Rosenquist P, Berggren J, Hernandez-Palacios JE, Dahlstrand U, Reistad N, Sheikh R, Malmsjö M. Hyperspectral and Laser Speckle Contrast Imaging for Monitoring the Effect of Epinephrine in Local Anesthetics in Oculoplastic Surgery. Ophthalmic Plast Reconstr Surg 2022; 38:462-468. [PMID: 35470293 PMCID: PMC9462134 DOI: 10.1097/iop.0000000000002163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE Epinephrine is used in local anesthetics to induce vasoconstriction and thus reduce bleeding and prolong the anesthetic effect. Finding the optimal delay between the administration of the anesthetic and skin incision to ensure vasoconstriction and minimize bleeding is important and has recently become the subject of debate. This is the first study to assess blood perfusion and oxygen saturation (sO 2 ) simultaneously in response to a local anesthetic containing epinephrine in human oculoplastic surgery. METHODS A local anesthetic consisting of lidocaine and epinephrine (20 mg/ml + 12.5 μg/ml) was injected in the eyelids of 9 subjects undergoing blepharoplasty. The perfusion and sO 2 of the eyelids were monitored using laser speckle contrast imaging and hyperspectral imaging, respectively. RESULTS Laser speckle contrast imaging monitoring showed a decrease in perfusion over time centrally at the site of injection. Half-maximum effect was reached after 34 seconds, and full effect after 115 seconds, determined by exponential fitting. The drop in perfusion decreased gradually further away from the injection site and hypoperfusion was less prominent 4 mm from the injection site, with a spatially dependent half-maximum effect of 231 seconds. Hyperspectral imaging showed only a slight decrease in sO 2 of 11 % at the injection site. CONCLUSIONS The optimal time delay for skin incision in oculoplastic surgery is approximately 2 minutes after the injection of lidocaine with epinephrine. Longer delay does not lead to a further decrease in perfusion. As sO 2 was only slightly reduced after injection, the results indicate that the use of epinephrine is safe in the periocular region.
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Affiliation(s)
- Josefine Bunke
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
| | - Aboma Merdasa
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
- Department of Physics, Lund University, Lund, Sweden
| | - Magne Stridh
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
| | - Pernilla Rosenquist
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
| | - Johanna Berggren
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
| | | | - Ulf Dahlstrand
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
| | - Nina Reistad
- Department of Physics, Lund University, Lund, Sweden
| | - Rafi Sheikh
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
| | - Malin Malmsjö
- Department of Clinical Sciences Lund, Ophthalmology, Lund University and Skåne University Hospital, Lund, Sweden
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de Keijzer IN, Massari D, Sahinovic M, Flick M, Vos JJ, Scheeren TWL. What is new in microcirculation and tissue oxygenation monitoring? J Clin Monit Comput 2022. [PMID: 35275312 DOI: 10.1007/s10877-022-00837-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2022] [Indexed: 12/24/2022]
Abstract
Ensuring and maintaining adequate tissue oxygenation at the microcirculatory level might be considered the holy grail of optimal hemodynamic patient management. However, in clinical practice we usually focus on macro-hemodynamic variables such as blood pressure, heart rate, and sometimes cardiac output. Other macro-hemodynamic variables like pulse pressure or stroke volume variation are additionally used as markers of fluid responsiveness. In recent years, an increasing number of technological devices assessing tissue oxygenation or microcirculatory blood flow have been developed and validated, and some of them have already been incorporated into clinical practice. In this review, we will summarize recent research findings on this topic as published in the last 2 years in the Journal of Clinical Monitoring and Computing (JCMC). While some techniques are already currently used as routine monitoring (e.g. cerebral oxygenation using near-infrared spectroscopy (NIRS)), others still have to find their way into clinical practice. Therefore, further research is needed, particularly regarding outcome measures and cost-effectiveness, since introducing new technology is always expensive and should be balanced by downstream savings. The JCMC is glad to provide a platform for such research.
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Tomanič T, Rogelj L, Milanič M. Robustness of diffuse reflectance spectra analysis by inverse adding doubling algorithm. Biomed Opt Express 2022; 13:921-949. [PMID: 35284194 PMCID: PMC8884198 DOI: 10.1364/boe.443880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/12/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Analysing diffuse reflectance spectra to extract properties of biological tissue requires modelling of light transport within the tissue, considering its absorption, scattering, and geometrical properties. Due to the layered skin structure, skin tissue models are often divided into multiple layers with their associated optical properties. Typically, in the analysis, some model parameters defining these properties are fixed to values reported in the literature to speed up the fitting process and improve its performance. In the absence of consensus, various studies use different approaches in fixing the model parameters. This study aims to assess the effect of fixing various model parameters in the skin spectra fitting process on the accuracy and robustness of a GPU-accelerated two-layer inverse adding-doubling (IAD) algorithm. Specifically, the performance of the IAD method is determined for noiseless simulated skin spectra, simulated spectra with different levels of noise applied, and in-vivo measured reflectance spectra from hyperspectral images of human hands recorded before, during, and after the arterial occlusion. Our results suggest that fixing multiple parameters to a priori known values generally improves the robustness and accuracy of the IAD algorithm for simulated spectra. However, for in-vivo measured spectra, these values are unknown in advance and fixing optical parameters to incorrect values significantly deteriorates the overall performance. Therefore, we propose a method to improve the fitting performance by pre-estimating model parameters. Our findings could be considered in all future research involving the analysis of diffuse reflectance spectra to extract optical properties of skin tissue.
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Affiliation(s)
- Tadej Tomanič
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, 1000 Ljubljana, Slovenia
| | - Luka Rogelj
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, 1000 Ljubljana, Slovenia
| | - Matija Milanič
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, 1000 Ljubljana, Slovenia
- Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
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Rogelj L, Simončič U, Tomanič T, Jezeršek M, Pavlovčič U, Stergar J, Milanič M. Effect of curvature correction on parameters extracted from hyperspectral images. J Biomed Opt 2021; 26:JBO-210189R. [PMID: 34490762 PMCID: PMC8420878 DOI: 10.1117/1.jbo.26.9.096003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE Hyperspectral imaging (HSI) has emerged as a promising optical technique. Besides optical properties of a sample, other sample physical properties also affect the recorded images. They are significantly affected by the sample curvature and sample surface to camera distance. A correction method to reduce the artifacts is necessary to reliably extract sample properties. AIM Our aim is to correct hyperspectral images using the three-dimensional (3D) surface data and assess how the correction affects the extracted sample properties. APPROACH We propose the combination of HSI and 3D profilometry to correct the images using the Lambert cosine law. The feasibility of the correction method is presented first on hemispherical tissue phantoms and next on human hands before, during, and after the vascular occlusion test (VOT). RESULTS Seven different phantoms with known optical properties were created and imaged with a hyperspectral system. The correction method worked up to 60 deg inclination angle, whereas for uncorrected images the maximum angles were 20 deg. Imaging hands before, during, and after VOT shows good agreement between the expected and extracted skin physiological parameters. CONCLUSIONS The correction method was successfully applied on the images of tissue phantoms of known optical properties and geometry and VOT. The proposed method could be applied to any reflectance optical imaging technique and should be used whenever the sample parameters need to be extracted from a curved surface sample.
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Affiliation(s)
- Luka Rogelj
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Urban Simončič
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
- Jozef Stefan Institute, Ljubljana, Slovenia
| | - Tadej Tomanič
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Matija Jezeršek
- University of Ljubljana, Faculty of Mechanical Engineering, Ljubljana, Slovenia
| | - Urban Pavlovčič
- University of Ljubljana, Faculty of Mechanical Engineering, Ljubljana, Slovenia
| | | | - Matija Milanič
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
- Jozef Stefan Institute, Ljubljana, Slovenia
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