Patent Description:
The accuracy of clinical melanoma clinical diagnosis is only at <NUM>% and strongly relies on the experience of the physician-dermatologist carrying out an analysis. The use of non-invasive imaging tools in clinical dermatology practice increases the accuracy of melanoma (malignant melanocyte-derived skin tumor) diagnosis by <NUM>% to <NUM>%. Dermatoscopes were the earliest devices used in dermatology. <CIT> ) discloses a structure of a dermatoscope which has light emitting diodes set forth (arranged) around the optical magnification device illuminating the test area. Instead of many optical waveguides, one conical prism is used, which has light-emitting diodes on the base and whose cone angle is designed in such a way that the light spreads on the main surface from light-emitting diodes. Reflected and scattered light from the surface structures of the skin is visible to the eye. Another non-invasive method of skin tumors imaging that was introduced in dermatology practice comparatively recently is spectrophotometric intracutaneous analysis. It is based on multispectral imaging of skin tumors by use of light sources of different wavelength: red, blue, green and infrared. Skin tissue chromophores (melanin, hemoglobin, and collagen) absorb light up to <NUM> in depth. <CIT>) describes an image processing method and device for analysis of the spatial arrangement of surface tissue chromophores. The device described consists of a digital camera and an RGB image processing algorithm that displays a skin chromophore arrangement by creating an output image.

Computerized analysis and decision support information system is integrated in order to avoid any dependence on the investigator's experience. It automatically analyzes recorded optical images of pigment skin lesions and provides an estimation of malignancy.

Document <CIT>) describes a computer analysis system based on quantification of skin tumor images recorded by dermatoscope and tumor classification.

<CIT>) describes a device and a method to be used in the detection of pathological skin lesions by non-invasive way. An application of this method enables to find and identify different types of moles, tumors, lesions, and cancer diseases (melanoma) by a complex analysis of visible and infrared optical signals, on the basis of integral and spectral modes.

An assay of high-frequency (> <NUM>) ultrasound is used in dermatology to determine the thickness of the skin or skin pathology by in vivo conditions. <CIT>) describes a device for measuring tissue thickness based on ultrasonic wave transmission. The device consists of remote control and data processing units and manual ultrasonic transducer properly aligned with the tissues. A device for measuring muscle and fat tissue thickness records only one reflection signal. Document <CIT>) describes an ultrasonic method and device for classification and visualization of different tissue types. The storage of clinical data, ultrasound radiofrequency (RD) data and the results of histological tests are included in the aforementioned document. Clinical and ultrasound RD data are provided as input variables for classifier training, which assigns the probability of cancer (a certain estimate) to each pixel on the ultrasound image. The probabilistic estimates of cancer are divided into ranges that can be set by the user when choosing threshold values. Different color or grayscale value is assigned to different ranges to distinguish suspicious areas in real time. This produces a parametric image corresponding to the actual ultrasound image. This can be useful for doctors in taking a biopsy to determine which area of tissue is most appropriate for taking the sample. Meanwhile, in the case of suspicion of melanoma, histological studies of skin tumors allow excising all tumors with certain determined reserve limits. If a histological examination reveals that the malignant tumor has not been removed radically, the removal should be repeated.

This description provides a system that automatically analyzes and evaluates skin tumor spectrophotometric images while recorded ultrasound data also provides a skin tumor malignancy rating by assigning it to one of the classes (benign or malignant).

The described skin non-invasive diagnostic solutions have the following disadvantages in comparison with the solution presented in this description:.

Publication<NPL> discloses an ultrasound (US) and optical non-invasive methods suitable for use in combination, to determine whether a hybrid multivariate approach may eventually be able to provide an objective aid to skin cancer diagnosis in primary care. A high frequency 3D US scanner are modified for C-scan, surface echo tracking and reflex transmission imaging. The images are co-registered with colour photographs and with images from a purpose-built spectrophotometric camera. The US system is used to scan <NUM> suspicious pigmented skin lesions referred from primary care. Nine are also examined using the imaging spectrophotometer. Regions of interest (ROIs) are drawn on ultrasound (US) images using the boundaries of pigmented lesions on co-registered photographs. Numerical US characteristics are then extracted for each lesion, providing a relative measure of US surface reflectance, intra-lesional US reflectance, total US attenuation, and the relative homogeneity of each characteristic. The methods for measuring depth of a tumour with respect to skin surface uses only time domain analyses of the ultrasound scans.

Publication<NPL> discloses use of spectrophotometry and ultrasound to quantitatively measure radiation-induced skin discoloration and subcutaneous-tissue fibrosis. This study investigated the association between skin discoloration and fibrosis in breast cancer patients who had undergone radiotherapy. Treated and untreated breasts were scanned using a spectrophotometer and an ultrasound. A spectrophotometer was used to measure the melanin and erythema indices of the skin, which were then used to quantify the degree of skin discoloration. The severity of fibrosis was quantitatively assessed using two ultrasound parameters: skin thickness and Pearson. coefficient of the hypodermis. The method for measuring depth of a tumour with respect to skin surface uses only time domain analyses of the ultrasound scans.

This document describes method for analyzing skin tumor data recorded by different physical imaging techniques of superficial tissue, for providing information on the expansion of tumor both on the surface and in depth of superficial tissues. The method contribute to the acceleration of a proper decision regarding diagnosis (malignant or non-malignant tumor), selection of follow-up tests, and planning treatment tactics.

The method for identifying malignant or non-malignant melanocyte-derived skin tumors, and more specifically, the method for assessing complex data on skin tumors recorded by spectrophotometry and ultrasound techniques, are described. A system used in the method consists of a high frequency (<NUM>) portable (operating via USB connection) ultrasonic device for in vivo skin examination, an optical spectrophotometric device with different wavelength light sources (red, blue, green and infrared) for registration of resolution and spatial distribution of skin chromophore (melanin, hemoglobin and collagen), and the complex data processing algorithm, which provides a diagnostic estimate of a recommendatory nature (malignant or non-malignant skin tumor). The proposed technical solution makes the automatic aggregation (fusion) of data and quantitative estimation obtained for melanocyte-derived skin tumors by different imaging techniques possible; it facilitates the acceptance of the final clinical diagnosis and further planning of treatment tactics.

This description provides a method to recognize human skin tumors (malignant or non-malignant) in a non-invasive way. The analysis method is for doctors of various specializations and/or other medical professionals who work with patients complaining of suspicious pigmented skin lesions. The system used in the method consists of a spectrophotometric intracutaneous analytical device and a high frequency (more than <NUM>) ultrasonic imaging device that collects data from a two-dimensional section (B- type image); a personal computer used by a physician with specialized software and algorithm installed for image analysis, data analysis, automatic classifier and visualization.

A database is accumulated to obtain the classification results, where the actual diagnosis of the injury is established during the histological examination of the section of the removed tumor. The data of the database is used for the training of the automatic tumor classifier (malignant or non-malignant) installed in specialized software. The study comprehensively evaluates images and data recorded by two non-invasive imaging techniques (spectrophotometric and ultrasonic) acting on different physical principles, and it is not limited to the strengths or weaknesses of any single method. The analysis is done automatically, it does not dependent on the examiner's experience, and can be used by an inexperienced dermatologist or therapist.

An efficient examination of the skin tumor on the surface and in-depth (changes in the internal structure of the tissues) is provided by non-invasive and safe for a patient way (spectrophotometry (<NUM> ) and ultrasound imaging (<NUM>)).

In <FIG> a schematic diagram of the components of the spectrophotometric and ultrasound imaging and data analysis system for use in the method according to the invention is presented.

Method according to the invention is a method for analysis of spectrophotometry and ultrasound images and data for the classification of skin tumors. The method comprises:.

Distinguishing of tumor area by the ultrasound imaging device (<NUM>) in the recorded data is performed using a local area spectral parameter of ultrasonic signal that has crossed the tumor area, and in that estimating quantitative parameters of images recorded by the spectrophotometric intracutaneous analyses device (<NUM>) comprises parameterizing of the selected informative area of the image and evaluating parameters of the surface shape of the tumor. During separation of tumor area in the images recorded by spectrophotometric intracutaneous analyses device (<NUM>) blue component of dermatoscopic image is used to define contour of the tumor area and optimal threshold is determined using the Otsu method. Estimating quantitative parameters of images recoded by the ultrasound imaging device (<NUM>) comprises parameterizing data of images the ultrasound imaging device (<NUM>) using spectral parameters of the contoured regions of tumor, tumor form parameters, and image texture parameters of the first and second range internal sections of the tumor.

The above disclosed features of the method are essential features of the invention. A system for use to carry out the method of analysis of spectrophotometry and ultrasound images and data for the classification of skin tumors is suitable for doctors of various specializations (e.g., dermatologists, plastic surgeons, therapists) and/or other medical professionals who work with patients complaining of suspiciously pigmented skin lesions. The system includes the following devices (<FIG> ):.

In addition to the devices listed above, the system also includes a server-based database (<NUM>), where the data obtained by spectrophotometric and ultrasonic imaging devices is recorded, data for analysis can be read, and a quantitative parameter base for training of the automatic classifier is stored. Besides the listed devices, the system further includes the necessary technical means to ensure the interconnection of the devices for data exchange.

The camera of the spectrophotometric intracutaneous analysis device (<NUM> ) (<FIG> ) is placed on the skin area to be examined on the patient, and dermatoscopic images, images of hemoglobin, collagen, epidermal and dermal melanin distribution in the skin are recorded. Cutaneous lesion to be examined should fit into the imaging window of the spectrophotometric device. If an incomplete image of the damage is recorded, the quantified parameters and the proposed malignancy estimate may be inaccurate. The camera of the spectrophotometric instrument must be immobilized (stable) during video recording; without proper recording of the lesion image, the test must be repeated. Recorded images are stored in the database (<NUM>). The histological examination data included into the server-based database (<NUM>), if possible, is used for the training of the automatic tumor classifier (malignant or non-malignant) installed in the specialized software (<NUM>) on the doctor's workstation computer.

High frequency (more than <NUM> MFIz) ultrasonic imaging device (<NUM>) (<FIG> ) which operates with a single-element mechanical scanning ultrasonic transducer is used for visualization of deeper skin structures. The data is collected during mechanical scanning when the ultrasonic transducer is sliding orthogonally on the skin surface and recording information as 2D skin section view (B-type image). Before scanning, the ultrasonic transducer holder with a nozzle, that maintains a constant distance between the ultrasonic transducer and the skin (for the skin's surface to be in the focus area of the ultrasonic transducer) is pressed to the skin in such a way that the transducer's scanning axis would match with the maximum diameter of the skin lesion as much as possible. The holder of the transducer is filled with distilled water of room temperature. Scanning locates where the visually visible skin damage (tumor) is the deepest. When this location is found, the scan stops and the image and its data are stored in the database (<NUM>). The ultrasonic imaging device stores not only the image but also the raw radiofrequency reflected ultrasonic signals that can be loaded and processed to obtain more quantitative information about tissue area and tissue structure of interest.

Recorded and stored skin lesion data are loaded and processed on a therapist's workstation computer (<NUM>) by the specialized software (<NUM>) and the algorithm that is capable of automatically processing of primary data, distinguishing, quantification and classification of the lesion. Clinical data, spectrophotometric images, ultrasound images and data, and histological results of the removed tumor are stored in the database and subsequently used for the classifier training to identify malignant skin tumors as accurately as possible.

The installed computer software (<NUM>) with image analysis, data analysis, automated classifier and image review algorithm (<NUM>) allows integration of the results obtained by different physical imaging techniques of superficial tissue (spectrophotometry (<NUM> ) and ultrasound imaging (<NUM>)). This makes it possible to increase the comprehensiveness, reliability, and accuracy of the diagnosis of malignant tumors.

Using specialized software (<NUM>) and database (<NUM>), analysis of spectrophotometric and ultrasound imaging data is performed automatically; skin tumors are automatically classified as malignant and non-malignant, not depending on investigators experience, and can, therefore, be used by an inexperienced dermatologist or therapist.

Claim 1:
A method of analysis of spectrophotometry and ultrasound images and data for the classification of skin tumors, comprising the following steps:
a) compiling a database (<NUM>) containing data recorded by a spectrophotometric intracutaneous analyses device (<NUM>) and an ultrasound imaging device (<NUM>);
b) recording dermatoscopic and individual skin chromophore spatial distribution images in light of different wavelengths emitted onto an area of interest of a skin;
c) recording B-type images of the area of interest of the skin using ultrasonic imaging device (<NUM>) operating at frequency over <NUM> for displaying structures beneath the skin surface;
d) computer processing (<NUM>) of images recorded by a spectrophotometric intracutaneous analyses device (<NUM>) and ultrasound imaging device (<NUM>) and generating values for a common general multidimensional data module;
distinguishing tumor area in data of images recorded by the spectrophotometric intracutaneous analyses device (<NUM>) and the ultrasound imaging device (<NUM>),
estimating quantitative parameters of images recorded by the spectrophotometric intracutaneous analyses device (<NUM>) and the ultrasound imaging device (<NUM>),
selecting informative parameters using the compiled database (<NUM>) and compiling a multi-dimensional data module of skin tumor for processing multi-dimensional data module in accordance with the database (<NUM>)
characterized in that
distinguishing of tumor area by the ultrasound imaging device (<NUM>) in the recorded data is performed using a local area spectral parameter of ultrasonic signal that has crossed the tumor area, and in that estimating quantitative parameters of images recorded by the spectrophotometric intracutaneous analyses device (<NUM>) comprises parameterizing of the selected informative area of the image and evaluating parameters of the surface shape of the tumor where during separation of tumor area in the images recorded by spectrophotometric intracutaneous analyses device (<NUM>) blue component of dermatoscopic image is used to define contour of the tumor area and optimal threshold is determined using the Otsu method, and estimating quantitative parameters of images recoded by the ultrasound imaging device (<NUM>) comprises parameterizing data of images the ultrasound imaging device (<NUM>) using spectral parameters of the contoured regions of tumor, tumor form parameters, and image texture parameters of the first and second range internal sections of the tumor.