A time-resolved scanning optical mammograph operating at 683, 785, 913, and 975 nm was developed and is presently used in a multi-centric clinical trial, allowing the collection of data from 101 patients with 114 malignant and benign lesions, up to October 2002. Late gated intensity and effective scattering images are routinely used for the detection and characterization of breast lesions.

Two systems for time-resolved diffuse spectroscopy were used for the optical characterization of the female breast in 4 volunteers. A first system was a compact laser diode instrument operated at 660 and 785 nm, while the second one was a broadband laboratory set-up based on mode-locked lasers tunable in the 610-1000 nm range. Measurements were obtained both in transmittance and in reflectance geometry at 5 inter-fiber distances ranging from 1 to 4 cm at different locations on the breast. Distinct spectral features both in absorption and in scattering were observed among the 4 volunteers, and for each subject between reflectance and transmittance measurements. These differences are correlated with the abundance of the glandular tissue and blood absorption. Upon increasing the inter-fiber distance in reflectance, deeper tissue structures were investigated, generally resulting in higher water contribution.

We report preliminary findings from a study of patient-volunteer experience in a clinical trial of optical mammography. We hypothesise that this qualitative data can usefully supplement the technical data collected during clinical tests and be of practical value in decision-making about design modifications, development priorities, and improving acceptability to patients. Findings from interviews with volunteers to date suggest that this method may establish new design criteria not deducible from routine data collection.

We report a novel perturbation approach for time-resolved transmittance imaging in diffusive media. The model relies on the method of Pade approximants and consists in a nonlinear approximation of time-resolved transmittance curves in presence of an inclusion. The ability of the proposed method to quantify tissue optical properties at different wavelengths for reconstruction of tissue constituents was tested on in vivo data of breast lesions from multi-wavelength time-resolved optical mammography

A portable instrument for tissue oximetry based on time-resolved reflectance spectroscopy was developed. The performances of the system were tested on phantoms in terms of stability, reproducibility among channels, and accuracy in the determination of the optical properties. Preliminary in vivo measurements were performed on healthy volunteers to monitor spatial changes in calf (medial and lateral gastrocnemius) oxygen hemoglobin saturation and blood volume during dynamic plantar flexion exercise.

The aim of this study was to investigate local muscle oxygen consumption (mVO₂) during various protocols of isometric handgrip exercise. mVO₂was measured by near-infrared spectroscopy (NIRS) during sustained, rhythmic, and intermittent isometric handgrip exercise. Whereas rhythmic handgrip exercise has the advantage that local muscle metabolism can be measured over the full range from low- to high-intensity work, the advantage of sustained handgrip exercise is that it is less prone to movement artifacts. Intermittent isometric handgrip exercise enables calculation of mVO₂ at short time intervals providing information about the time response of local oxygen consumption in relation to the onset of exercise. Ten healthy subjects participated in this study. The different protocols were performed on separate days and in random order. mVO₂ during rhythmic exercise was significantly higher than that during sustained exercise at all work intensities tested (P ≤ 0.05). However, the highest oxygen consumption value for the three exercise protocols was measured during the steady state of intermittent exercise (P ≤ 0.05). These results show that the measurement of task-specific muscle metabolism during exercise can be measured noninvasively and with relative ease by near-infrared spectroscopy.

Inflammatory processes as they occur during rheumatoid arthritis (RA) lead to changes in the optical properties of joint tissues and fluids. These changes occur early on in the disease process and can potentially be used as diagnostic parameter. In this work we report on in vivo studies involving 12 human subjects, which show the potential of diffuse optical tomographic techniques for the diagnosis of inflammatory processes in proximal interphalangeal (PIP) joints.

The experimental results of NIR optical tomographic imaging on human limbs are shown in this paper. The absolute absorption and scattering images roughly revealed the anatomical structure of the targets, where the bones were distinguished from the muscle. The images of the hemoglobin concentration changes calculated from differential image of absorption at two wavelengths showed the physiological phenomena during the forearm exercise.

A portable sensor device for simultaneous detection and processing of skin-remitted optical signals from any two sites of the body has been developed and tested. The photoplethysmography (PPG) principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. The newly developed two-channel approach allows to estimate the vascular blood flow resistance by analysis of time shifts between the PPG pulses detected at different body sites. Potential of the sensor device for express-assessment of human cardio-vascular condition and for body fitness tests has been demonstrated.

The laser Doppler flowmetry technique has recently been used to report a significant transient increase of the cutaneous blood flow signal when a local non-noxious pressure is applied progressively on the skin (11.1 Pa/s). The present work analyses the dynamic characteristics of this vasodilatory reflex response on anaesthetised rats. A de-noising algorithm using wavelets is proposed to obtain accurate values of these dynamic characteristics. The blood flow peak and the time to reach this peak are computed on the de-noised recordings. The results show that the mean time to reach the peak of perfusion is 85.3 s (time t = 0 at the beginning of the pressure application). The mean peak value is 188.3 arbitrary units (a.u.), whereas the mean value of the perfusion before the pressure application is 113.4 a.u. The mean minimum value obtained at the end of the experiment is 60.7 a.u. This latter value is, on the average, reached 841.3 s after the beginning of the pressure application. The comparison of the dynamic characteristics, computed with the de-noising algorithm on signals obtained in other situations, will give a better understanding on some cutaneous lesions such as those present on diabetic people.

Two systems for measurements of absorption and scattering properties, based on picosecond-pulse lasers and singlephoton counting detection, were characterized using a detailed protocol. The first system utilizes diode lasers at 660, 785, 910 and 974 nm as light sources. The second employs a Ti:sapphire and a mode-locked dye laser to produce tunable pulses in the range 610 - 1000 nm. Using solid tissue phantoms, the systems were rigorously characterized and compared in terms of absolute accuracy of the measured scattering and absorption coefficients, the linearity over the parameter range, the precision with respect to injected light energy, the stability over time, and the reproducibility of the results. The phantoms were made of epoxy resin with TiO as scatterer and black toner powder as absorber.

A procedure for retrieving the optical properties of a two-layered diffusive medium based on an exact analytical solution of the time dependent diffusion equation and on multidistance reflectance data is presented. The method overcomes some limitations of previously developed procedures. Five parameters have been always fitted: the absorption and the reduced scattering coefficient of both layers and the thickness of the first layer. The results obtained have shown that this procedure does not require an initial guess for the unknown optical parameters fitted, whilst the start value for the thickness of the first layer needs to be estimated within an error of about 50%. Time resolved measurements of diffuse reflectance have been generated with Monte Carlo simulations. A particular attention has been devoted to determine the optical properties of the muscle with the subcutaneous fat layer.

For many clinical light applications, such as photodynamic therapy (PDT), the therapeutic effect strongly depends on the light dose in a certain tissue depth. A measure for the attenuation and penetration of light in tissue is the optical penetration depth, which is derived from the tissue’s optical properties at a certain wavelength. Therefore, in vivo measurements to determine the optical properties were performed of the bladder wall (n = 12) and brain tissue (n = 11) on patients undergoing photodynamic therapy. The tip of a 400 μm bare fiber was placed in contact with the investigated tissue, either during open surgery (brain) or through the working channel of a cystoscope (bladder wall). Light of the wavelengths 420-450 nm, 532 nm, and 635 nm was coupled alternately into the fiber. The diffuse backscattered light was detected spatially resolved by means of a CCD camera. Additionally, the total diffuse reflectance of the tissue site was determined, by relating the white light spectra remitted from the tissue to that of a reflectance standard. These two independent measurements were fitted with Monte Carlo simulations. Thus, the reduced scattering and absorption coefficient could be obtained and the optical penetration depth was derived. The presented investigations showed that spatially resolved diffuse reflectance in combination with total diffuse remission provides a valuable method to determine tissue optical properties in vivo. Two human organs were analyzed with this technique and both, bladder wall tissue and brain tissue showed reproducible results.

Monte Carlo simulations and experiments in tissue-simulating phantoms were performed to study the accuracy of fluorophore concentrations recovered using a diffusion theory model of fluorescence. Fluorophore concentration was measured using three fluorophores with an overall root-mean-square accuracy of 13.7%. These experiments were compared with concentration measurements by diffuse reflectance spectroscopy, which were less accurate for all three fluorophores. Monte Carlo simulations were also used to examine the ability of the model to recover concentration from layered fluorophore distributions.

We present a novel method, space-space MUSIC (MUltiple SIgnal Classification), to localize three-dimensionally focal fluorophore-tagged lesions activated subsequently by different laser source posi-tions from multi-sensor fluorescence data obtained from a single measurement plane. Matches between a signal subspace derived from the measured data and data from model spots allow 3D determination of the centers-of-gravity of fluorescence regions. Simulated spots in bounded, inho-mogeneous media could be localized accurately. The algorithm has shown to be robust against patient-dependent parameters, such as optical background parameters. The algorithm does also not consider medium boundaries.

NIRS signals measured on the adult head contain contributions from the brain and from overlying tissue. It was shown recently that measured distributions of times of flight (DTOF) of photons allow to deduce absorption changes occurring in different layers of the head. This method relies on time-dependent mean partial pathlengths calculated by Monte Carlo simulations for assumed background optical properties of the various tissues. Deconvolution of the measured DTOF is required using the instrumental response function. We propose an alternative method to estimate absorption changes in various tissue layers by analyzing changes of moments of DTOFs (integral, mean time of flight and variance) recorded at various source-detector separations. The sensitivity factors corresponding to integral, mean time of flight and variance were obtained by Monte Carlo simulations for a layered model of the head. From experimentally derived mean time of flight and variance the contributions of the instrumental response function were subtracted. The proposed method was applied to multi-distance time-domain measurements during functional stimulation of the brain of healthy volunteers.

Since a functional near-infrared spectroscopy monitor is a small and flexible tool, it can well be integrated with blood flow monitors. In the first part of the publication we show, that laser-doppler-flow measurements on the scalp return stimulus induced blood-volume changes. The effect of these changes on CW-NIRS measurements is demonstrated using frequency-domain-system capable of distinguishing absorption changes in superficial layers from those in the bulk tissue. The relationship between cerebral blood flow and cerebral hemoglobin concentration is studied in the second part of the publication. We present a visual stimulation experiment where changes in posterior cerebral artery flow velocity (PCA-Fv) were continuously monitored bilaterally by transcranial doppler sonography. Combining this approach with CW-NIRS imaging shows that the change in the arterial blood flow velocity occur approximately 1s before the deoxy-hemoglobin changes.

Knowledge of the baseline optical properties of the tissues of the human head is essential for absolute cerebral oximetry, and for quantitative studies of brain activation. In this work we numerically model the utility of signals from a small 6-optode time-resolved diffuse optical tomographic apparatus for inferring baseline scattering and absorption coefficients of the scalp, skull and brain, when complete geometric information is available from magnetic resonance imaging (MRI). We use an optical model where MRI-segmented tissues are assumed homogeneous. We introduce a noise model capturing both photon shot noise and forward model numerical accuracy, and use Bayesian inference to predict errorbars and correlations on the measurments. We also sample from the full posterior distribution using Markov chain Monte Carlo. We conclude that ~ 10⁶ detected photons are sufficient to measure the brain’s scattering and absorption to a few percent. We present preliminary results using a fast multi-layer slab model, comparing the case when layer thicknesses are known versus unknown.

One of the primary applications of diffuse optical imaging is to localize the changes in the cerebral oxygenation during physical or mental activities. Up to now, data from an optical imager is simply presented as a two-dimensional (2-D) topographic map using the modified Beer-Lambert law that assumes the homogeneous optical properties beneath each optode. Due to the highly heterogeneous nature of the optical properties in the brain, the assumption are evidently invalid, leading to both low spatial resolution and inaccurate quantification in the assessment of hemodynamic changes. To cope with the difficulties, we propose a nonlinear image reconstruction algorithm for a two-layered slab geometry using time-resolved reflected light. The algorithm is based on the previously developed generalized pulse spectrum technique, and implemented within a semi three-dimensional (3-D) framework to conform to the topographic visualization and to reduce computational load. We demonstrate the advantages of the algorithm in quantifying simulated changes in hemoglobin concentrations and investigate its robustness to the uncertainties in the cortical structure and optical properties. The methodology is also validated with experiments on a layered phantom.

It is important for near-infrared imaging to estimate the sensitivity of detected signal to the change in absorption of tissue resulting from brain activation and the volume of tissue interrogated for a specific source-detector spacing. In this study, light propagation in adult head models is predicted by Monte Carlo simulation in order to investigate the effect of the thickness of the superficial tissues on the partial optical path length in the brain and on the spatial sensitivity profile. The effect of thickness of skull on the partial optical path length and spatial sensitivity profile is almost the same as that of the scalp. The effect of thickness of cerebrospinal fluid layer on the partial optical path length and spatial sensitivity profile is different from that of the scalp and skull. The partial optical path length mainly depends upon the depth of inner skull surface whilst the spatial sensitivity profile is considerably affected by the thickness of the cerebrospinal fluid layer.

Activation of the cerebral cortex induces a localized change in the volume and oxygenation of the blood. Because the change in spectral reflectance of the cortex depends upon the concentration changes in oxy- and deoxy haemoglobin, multi-spectral imaging has been applied to investigate the functional activity of the exposed cortex related to oxy- and deoxy haemoglobin. However, brain tissue is a highly scattering medium, and the reflectance of cortical tissue depends on the mean optical path length of the detected light. The linear spectrographic analysis method without wavelength-dependent path length scaling may produce unreliable results in multi-spectral image analysis. In this study, we propose a method of estimating the wavelength-dependent path length factor from the principal component analysis of the multi-spectral images of the exposed cortex. The optical path-length factor estimated from the first principal component of the multi-spectral image of the cortical model and the absorption spectrum of haemoglobin agrees with that predicted by Monte Carlo simulation. The tendency of the optical path-length factor of the pig brain estimated from the first principal component of the multi-spectral images is almost the same as that of the cortical model.

The principle of acousto-optic imaging is to combine coherent light and ultrasound in biological tissues to detect optical contrasts with a spatial resolution close to that of echography. Here we propose a model to describe the propagation of acoustically modulated light in a scattering medium. To do so, we derive a correlation diffusion equation from a correlation transport equation making a few approximations. We express solutions of this diffusion equation and compare them with Monte Carlo simulations in the case of uniform and localized insonifications.

The optical coherence tomography (OCT) has been successfully applied to diagnostic imaging of transparent ocular organs. In case of highly scattering tissues such as skin and mucous membrane, and the OCT signal includes noise component due to multiple scattering in tissue, the characteristics of the OCT signal from the highly scattering tissue is more complex. In this study, we investigate the characteristics of the OCT signal from the low-scattering and highly scattering tissues by Monte Carlo simulation. In case of low-scattering tissue, the intensity of the signal is maximised when the focal depth equals the probing depth and the spurious peak of the noise due to scattering is observed at the focal depth in the OCT image. In case of highly scattering tissue, the intensity of the signal is maximised when the focal depth is smaller than the probing depth and the noise is almost independent of the focal depth.

The knowledge of the scattering phase function, which describes the angular intensity distribution of the scattered light, is important for modeling the light propagation in turbid media. This is especially true for structured media, where light propagation is anisotropic, leading to direction-dependent reflected or transmitted intensity profiles. We investigated scattering by combining analytical solutions and finite difference time domain (FDTD) simulations of the Maxwell equations with two-axes goniometric experiments. Using polystyrene spheres and cylindrical phantoms the methods were successfully validated. The phase functions of dentin slabs were measured and it is shown that the scattering of dentin tubuli resembles cylinder scattering.

We report on the effect of the nonlinear multiple passage on optical imaging of an absorption inhomogeneity of finite size deep inside a turbid medium based on a cumulant solution to radiative transfer. An analytical expression for the nonlinear correction factor is derived. Comparison to Monte Carlo simulations reveals an excellent agreement. The implication on optical imaging is discussed.

A detailed investigation of the use of time-resolved reflectance and frequency-resolved reflectance for the optical characterization of scattering medium such as breast tissues based on the diffusion equation has been performed. Two different boundary conditions were imposed at the air-tissue interface : the first use the" zero real surface" (ZRS) , the second refers to the " zero extrapolated surface" (ZES). To simplify the preliminary analysis, the tissues have been assimilated to a semi-infinite geometry or a slab sufficiently thick. Among the results, the computation showed that at low frequency approximation, the determination of the phase angle shift is independent of whatever boundary conditions is applied. Consequently breast tissue optical properties would be retrieved by means of frequency resolved data (modulation and phase) recorded at two different radial distances. For modulated light at f≈20 MHz, and using a model accounting for simple ZRS formulation. Under thes approximations discrepancies are within 3% for a μ_a and 0.5% for μ'_s.

Optical imaging derived from intrinsic signals such as blood volume and flow has enabled us to characterize the area of brain activation. Multi-spectral imaging of the change in cortical reflectance allows the determination of the change in the oxy-hemoglobin concentration independent of the deoxy-haemoglobin concentration. The changes in blood volume and oxygenation are closely related to the cerebral blood flow, and hence the simultaneous measurement of blood volume and flow in the cortical tissue must be beneficial for investigation of functional brain activation. Laser speckle flowgraphy has also been developed to visualize the blood flow in tissue and has been applied to measure the blood flow in tissue. In this study, a functional imaging system has been designed and assembled for the simultaneous measurement of the change in blood volume and flow in tissue. The optical systems of multi-spectral imaging and laser speckle flowgraphy are attached to the photo ports of the beam-splitter attachment of a stereo-microscope. The data of the multi-spectral image and speckle pattern of phantoms and finger are obtained for the initial experiments with the proposed system.

Optical imaging of an exposed cortex for brain function measurement is an attractive method for both clinical and physiological investigations. Multi-spectral imaging of the exposed cortical tissue enables measuring the activity-dependent changes in oxy- and deoxy haemoglobin independently. Because light propagation in the cortical tissue strongly depends upon wavelength, the blurring by a scattering effect on multi-spectral images depends upon wavelength as well. It is important for more accurate measurement to correct this wavelength-dependent blurring in the multi-spectral images of the exposed cortex. In this study, the relative point spread functions which represent the difference in blurring by wavelength were predicted from the multi-spectral images of a blood vessel in the cortical tissue. The multi-spectral images of the cortical model are calculated by Monte Carlo simulation and wavelength-dependent point spread functions are estimated from the cross section of the blood vessel in the images. The tendency of the wavelength-dependence of relative point spread functions is almost the same as that of the point spread functions predicted from the light propagation in the cortical model. The relative point spread functions estimated from wide blood vessels are broader than those estimated from a narrow blood vessel.

A near infrared topographic system is an effective instrument for obtaining an image of brain activation. In the conventional mapping method, the signals detected with the source-detector pairs are simply mapped and interpolated to obtain the topographic image. It is likely that an image reconstruction algorithm using a spatial sensitivity profile will improve the spatial resolution of the topographic image. In this study, a one-dimensional distribution of the absorption change in the head model is calculated from the signals detected with various intervals of source-detector pairs by the conventional mapping method and an image reconstruction algorithm using the spatial sensitivity profile to evaluate the limit of spatial resolution of topographic imaging. Small intervals of the source-detector pairs improve the position of the absorption change in the topographic image calculated by both the conventional mapping method and the reconstruction algorithm. The size of the absorption change calculated from the intensity detected with a small interval of the source-detector pairs is sufficiently improved by the image reconstruction algorithm using the spatial sensitivity profile.

Near infrared topographic imaging is an effective instrument to image brain-cortex activity. The light scattering in tissue prevents us from improving the spatial resolution of the reconstructed image; hence it is important to evaluate the effect of scattering on the spatial resolution of the image. In this study, the light propagation in the adult head model was predicted by Monte Carlo simulation to investigate the effect of fiber arrangement on the spatial resolution of NIR topographic imaging. The image of absorbers in the topographic images obtained from the double-density arrangement of source-detector pairs was compared with that from the conventional single-density arrangement. The double density arrangement improved the spatial resolution and accuracy of the position of the absorbers in the topographic image.

Diffuse Optical Tomography (DOT) image reconstruction is a challenging 3D problem with a relatively large number of unknowns. DOT poses a typical ill-posed problem usually plagued by under-determination, which complicates the inverse problem. Conventional image reconstruction algorithms can not provide high spatial resolution and may become computationally expensive and unreliable especially in the presence of noise. In this work, we extend our previous formulation for the 3D inverse DOT problem, where we focus to improve the spatial resolution and quantitative accuracy of 3D DOT images by using anatomical a priori information, which is specific to the medium of interest. Maximum A Posteriori (MAP) estimate of the image is formed based on the formulation of the image's probability density function, which is extracted from the available a priori anatomical information. An ``alternating minimization'' algorithm, which sequentially updates the unknown parameters, is used to solve the resulting optimization problem. Proposed method is evaluated in a 3D simulation experiment. Results demonstrate that the proposed method leads to significantly improved spatial resolution, quantitative accuracy and faster convergence than standard and regularized least squares solutions even in the presence of noise. As a result, the approach demonstrated in this paper both addresses the ill-posedness and balances the computation complexity vs. image quality trade-off in the 3D DOT inverse problem.

Two time-domain scanning optical mammographs are presently tested in clinical trials within the EU project "OPTIMAMM" supported by the EC. To assess their performance (e.g., accuracy, sensitivity, stability), systematic measurements were performed on breast-like phantoms. Both, estimation of optical properties and acquisition of good contrast images for diagnostic purposes were considered. The proposed assessment procedure can be applied to characterize and improve other novel and existing instruments for photon migration imaging and spectroscopy.

We present a newly developed scanning time-resolved optical mammograph for breast cancer detection featuring four wavelengths for enhanced spectroscopic information, up to 6 off-axis detection channels for improved depth localisation and novel attenuation and imaging optics for improved response reproducibility and photon collection efficiency. First results on the characterisation and on performance tests of this mammograph are shown.

The combined effect of multiple light scattering and radiative transport on fluorescence decays is experimentally studied. The experimental setup consists of a 15 cm cubic cell containing a highly fluorescent dye solution and scatterers (either silica particles or milk). The effect of fluorophore concentration was studied, in the absence and presence of scatterer. The effect of excitation and detection geometry was also studied. It is concluded that light scattering can have a significant effect on the fluorescence decays, namely on the mean decay times, and the results can be explained on the basis of the spatial distributions of the successive generations of excited molecules.

In this study quantitative near-infrared-spectroscopy (NIRS) was investigated as a potential tool to measure local O₂ consumption (mVO₂) in human bone (tibia) in comparison with muscle (musculus tibialis anterior). Both tissues were examined at rest and during 80% maximum voluntary isometric muscle contraction. Fifteen subjects were tested. Local variations in oxy-hemoglobin (O₂Hb), desoxy-hemoglobin (HHb), and total hemoglobin (tHb) were investigated with a continuously operating NIRS system. mVO₂ was determined in phases of applied arterial occlusion. At rest mVO₂ was five times higher in muscle than in bone. However, both mVO₂ values showed a distinct correlation with skin-fold thickness. At rest and only in bone we recorded a periodical variation of O₂Hb. HHb was almost constant. This variation of O₂Hb and the resulting variation in tHb indicated chances in blood volume, which are not compatible with the solid nature of bone. During muscle contraction, mVO₂ in muscle increased about twenty fold. As expected, mVO₂ in bone did not significantly increase during muscle contraction. In conclusion, NIRS was confirmed as a valid method to determine the excess mVO₂ in muscle during contraction. For mVO₂ measurements in bone more sophisticated localization techniques are required to separate the effects derived from bone and skin.

Predicting concentrations of aqueous glucose solutions using reduced wavelength components is presented. The wavelengths are selected based on the second derivative of the near-infrared absorbance spectra. In the demonstration of the temperature-insensitive partial least squares analysis, good agreement between actual glucose concentrations and predicted values is verified.

Simultaneous temporal analysis of whole human or rat blood luminescence and erythrocytes sedimentation rate (ESR) in same blood using special computerized optoelectronic devices for single photon counting and for high temporal resolution of the rate of sedimentation of red blood/plasma boundary revealed correlation between both time series. Correlation was observed in vitro in normal blood, after action of physical (height of blood column) and of chemical (hydrogen peroxide) factors, and in experimental cerebral ischemia. An ischemia was invoked in rats by occlusion of both common carotid arteries. ESR was studied with the device "ESR-scan" and the dynamics of respiratory burst (RB) by a luminol-dependent luminescence method on the same blood samples. There was a noticeable increase of intensity of RB in whole rat blood and significant acceleration of ESR in blood diluted on 50% in 90 minutes after applying a ligature on carotid arteries. The individual differences between animals attesting to different degree of RB and ESR activation in blood both in intact animals and after operational intervention was obtained. Revealed correlation points to considerable relation between blood energy and its mechanical properties.

The new technique of biological medium structure estimation based on optical diffraction filtration method is represented. Biological medium is considered as a superposition of cluster molecular structures. Depending on wavelength of probing optical radiation, during scattering the different particles participate which make a unique volume diffraction grating for each wavelength. The probing radiation characteristics variation allow to estimate the structure of the researched medium. Experiments on studying of coherent and not coherent optical radiation with biological media interaction have been carried out. The images of rabbits tissues, human tissues in vivo and fluoroplastic images were processed. For the first time scattered radiation image processing technique based on signal decomposition of the Hermite functions which are the eigenfunctions of Fourier transform was applied for such class of tasks. It has allowed to reveal in strongly scattered radiation a structural component. Estimating the characteristics of a structural component it is possible to receive geometrical parameters appropriate to probing radiation diffraction grating. The offered technique is perspective for studying biological molecular structures and creating tomographs of a new class.