Laser speckle contrast imaging (LSCI) stands as a critical imaging modality capable of real-time acquisition of dynamic blood flow information, finding extensive utility in clinical and experimental settings requiring prompt feedback. While traditional Reflect Laser Speckle Contrast Imaging (R-LSCI) excels in superficial vascular imaging, Transmissive Laser Speckle Contrast Imaging (T-LSCI) offers superior performance in imaging deeper vascular structures. In this study, to harness the complementary strengths of R-LSCI and T-LSCI, we introduce a novel approach: the space domain contrast optimization algorithm. This method integrates laser speckle contrast images captured under both conditions through spatial domain processing and optimized contrast ratio selection. Our results demonstrate that the proposed method enhances vascular visualization and achieves superior vascular imaging outcomes when compared to R-LSCI and T-LSCI under space contrast (sK), a spatial domain method.
The laser speckle contrast imaging (LSCI) technique, based on dynamic light scattering theory, is a non-scanning method for blood flow imaging that offers wide-field coverage. However, under traditional single-exposure conditions, static scattering may interfere with imaging, leading to reduced contrast and diminished image clarity, thereby affecting the accuracy of blood flow monitoring in biological tissues. This study aims to address the challenge of static scattering under single-exposure conditions by employing the adaptive window space direction contrast (awsdk) imaging method proposed in the laboratory. Through validation in reflective systems using phantoms and rabbit ear regions, this research combines the awsdk imaging method with optimized single-exposure techniques, effectively correcting static scattering and eliminating the impact of system noise on speckle contrast. This approach not only enhances imaging quality but also enables rapid monitoring of blood flow changes using speckle contrast measurements under single-exposure conditions, providing an effective solution for further advancement of laser speckle contrast imaging technology.
KEYWORDS: Image restoration, Feature extraction, Associative arrays, Data modeling, Brain tissue, Image processing, Magnetic resonance imaging, 3D modeling, Signal to noise ratio, Tissue optics
Diffuse optical tomography (DOT) guided by medical images can be used to achieve real-time reconstruction of subdural hematoma images for monitoring purposes. However, when the hematoma is irregular and the signal to noise ratio(SNR) of input signal is low, the reconstruction effect of this method is not ideal. In order to alleviate this situation and improve the reconstruction effect of cerebral hematoma images, we proposed a optical image mapping feature extraction method in the paper. The result of experiment shows that the mean relative volume error (VRE) of the hematoma reconstruction model optimized by the optical image mapping feature extraction method is only 0.79%, and the mean value of the average Manhattan distance (AMD) between the reconstructed absorption coefficient and the true absorption coefficient is 0.0062mm-1. Compared with the model directly inputting optical information, the optical image mapping feature extraction method reduces the average VRE of the model by 93.3%, and the average AMD by 27.1%. This method provides a promising method for non-invasive continuous monitoring of clinical cerebral hematoma.
To overcome the ill-conditioning of the NIR fluorescence molecular tomography (FMT) inverse problem, neural networks are commonly used for reconstruction to improve the accuracy and reliability of imaging. This paper aims to investigate the impact of different neural network structures on the reconstruction performance of FMT for improved effect. In this study, the finite element solution of the Laplace-transformed time-domain coupled diffusion equation serves as the forward model for FMT, an improved stacked autoencoder (SAE) network is used and applied to FMT reconstruction. In the study, the SAE was set as a four layers network model structure, of which two layers were used for the hidden layer of the network. When the number of neurons in hidden layer 1 is smaller than hidden layer 2, the network is referred to as a decreasing network structure, and vice versa for an increasing network structure. The input data to the network consists of surface fluorescence intensity values collected by detectors around the heterogeneity. The output data of the network consists of fluorescence intensity values on partitioned nodes obtained through finite element method (FEM) partitioning. The experimental results demonstrate that the increasing network structure exhibits better imaging accuracy, fewer artifacts, and a more stable network model in FMT reconstruction. Through this study of the impact of SAE network architecture on FMT reconstruction, we have identified the optimal network model, which holds significant guidance for the application of neural networks in the field of FMT.
The stacked autoencoder (SAE) neural network applied to diffuse optical tomography (DOT) achieves accurate and stable detection of the position and size of tissue abnormality. The quality of modeling data influences the robustness and the accuracy of the model, the measurability of the model determines the effective range of the data cleaning method used in clinical practice. In order to determine the effective range of this method in clinical use, we analyze the measurability of anomaly detection based on DOT method. The analysis result is used as a priori information to clean the neural network sample data set used in this work. The results show that excluding the data outside the measurable range, the proposed method enables the network to achieve a prediction accuracy of 99% within the measurable range and achieves rapid and accurate detection of the position and size of abnormality in the tissue.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.