Speckle, a factor reducing image quality in optical coherence tomography ('OCT'), can limit the ability to identify cellular structures that are important for the diagnosis of a variety of diseases. The present invention allows for an implementation of an angular compounding, angular compounding by path length encoding ('ACPE') for reducing speckle in OCT images. By averaging images obtained at different incident angles, with each image encoded by path length, ACPE maintains high-speed image acquisition and implements minimal modifications to OCT probe optics. ACPE images obtained from tissue phantoms and human skin in vivo demonstrate a qualitative improvement over traditional OCT and an increased signal-to-noise ratio ('SNR'). Accordingly, apparatus probe catheter, and method are provided for irradiating a sample. In particular, an interferometer (5) may forward forwarding an electromagnetic radiation (10). In addition, a sample arm may receive the electromagnetic radiation, and can include an arrangement (20) which facilitates a production of at least two radiations (30, 40) from the electromagnetic radiation so as to irradiate the sample. Such arrangement can be configured to delay a first radiation of the at least two radiations with respect to a second radiation of the at least two radiations.

Speckle reduction in optical coherence tomography by path length encoded angular compounding

Exemplary method, apparatus and arrangement can be provided for obtaining information associated with a sample such as a portion of an anatomical structure. The information can be generated using first data, which can be based on a signal obtained from a location on the sample, and second data, where the second data can be obtained by combining a second signal received from the sample with a third reference signal. An image of a portion of the sample can also be generated based on the information. For example, the first data can be associated with spectral encoding microscopy data, and the second data can be associated with optical coherence tomography data.

Method and apparatus for optical imaging via spectral encoding

Clinical trials have shown that hyperthermia (HT), i.e. an increase of tissue temperature to 39–44 °C, significantly enhance radiotherapy and chemotherapy effectiveness [1]. Driven by the developments in computational techniques and computing power, personalised hyperthermia treatment planning (HTP) has matured and has become a powerful tool for optimising treatment quality. Electromagnetic, ultrasound, and thermal simulations using realistic clinical set-ups are now being performed to achieve patient-specific treatment optimisation. In addition, extensive studies aimed to properly implement novel HT tools and techniques, and to assess the quality of HT, are becoming more common. In this paper, we review the simulation tools and techniques developed for clinical hyperthermia, and evaluate their current status on the path from ‘model’ to ‘clinic’. In addition, we illustrate the major techniques employed for validation and optimisation. HTP has become an essential tool for improvement, control, and ...

https://www.tandfonline.com/doi/pdf/10.3109/02656736.2013.790092

Simulation techniques in hyperthermia treatment planning

An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. The tissue deformation parameter strain is determined by an accumulation of strain rate estimates for consecutive frames over an interval. The interval may be a triggered interval generated by, for example, an R-wave in an ECG trace. Three quantitative tissue deformation parameters, such as tissue velocity, tissue velocity integrals, strain rate and/or strain, may be presented as functions of time and/or spatial position for applications such as stress echo. For example, strain rate or strain values for three different stress levels may be plotted together with respect to time over a cardiac cycle. Parameters which are derived from strain rate or strain velocity, such as peak systolic wall thickening percentage, may be plotted with respect to various stress levels.

Method and apparatus for providing real-time calculation and display of tissue deformation in ultrasound imaging

An apparatus, method and software arrangement for imaging a surface of a structure that is in contact with an opaque fluid is provided. The apparatus includes an article of manufacture (e.g., a housing), a fluid delivery arrangement and an imaging arrangement. The housing includes an aperture formed in the article of manufacture. The fluid delivery arrangement is configured to deliver a volume of substantially transparent fluid to the aperture formed in the housing. The imaging arrangement is configured to image the surface of the structure using an imaging modality after the volume of the transparent fluid is delivered to the aperture, wherein the imaging arrangement and/or the article of manufacture is translated along the surface of the structure while imaging the surface of the structure.

Method and apparatus for imaging of vessel segments

PROBLEM TO BE SOLVED: To obtain an elastic deformation detecting method within a flexible organization by normalizing elastic coefficient estimated amount by using a diagonal normalizing matrix having shaft direction change functions to be imparted to each basic elastic coefficient value as coefficients so as to store each value within a uniform interval fixing a center in the vicinity of a specific average value. SOLUTION: The definition of a normalizing matrix R is to uniformly keep vector formed by a distance from an average value of an element e1 of an elastic coefficient vector (e). Uniform interval is defined and the normalizing matrix R is obtained from a sensitivity matrix S by using a simple matrix calculation to be executed in a system 200. At the last of a calculation 222 calculating the matrix R, an electronic system 200 related to an ultrasonograph executes a calculation 223 calculating a matrix M of estimated amount of the vector (e) and continuously executes a calculation 224 of a matrix multiplication of the matrix M and vector (d). By a repetition, a method to be enforced in the electronic system 200 related to the ultrasonograph is utilized and a reproduced image of the elastic coefficient (e) can be acquired based on change vector.

Elastic deformation detecting method and ultrasonograph

The decomposition of the time reversal operator (DORT) is a detection and focusing technique using an array of transmit-receive transducers. In the absence of noise and under certain conditions, the eigenvectors of the time reversal operator contain the focal laws to focus ideally on well-resolved scatterers even in the presence of strong aberration. This paper describes a new algorithm, FDORT, which uses focused transmission schemes to acquire the operator. It can be performed from medical scanner data. A mathematical derivation of this algorithm is given and it is compared with the conventional algorithm, both theoretically and with numerical experiments. In the presence of strong speckle signals, the DORT method usually fails. The influence of the speckle noise is explained and a solution based on FDORT is presented, that enables detection of targets in complex media. Finally, an algorithm for microcalcification detection is proposed. In-vivo results show the potential of these techniques.

Time reversal operator decomposition with focused transmission and robustness to speckle noise: Application to microcalcification detection

The invention relates to a method and a device for imaging a visco-elastic medium (2). The method comprises an excitation step during which an internal mechanical stress is generated in an excitation zone [A] and an imaging step of acquiring signals during the movements generated by the mechanical stress in the visco-elastic medium (2) in response to the internal mechanical stress in an imaging zone [B] that includes the excitation zone [A]. According to the invention, the method further comprises a step of calculating a quantitative index [Cij] associated with the Theological properties of the visco-elastic medium (2) at at least one point [Bij] of the imaging zone situated at a given depth outside the excitation zone [A]. The quantitative index [Cij] is representative of a comparison between signals acquired during the movements generated in response to the mechanical stress at at least one point [Aij] of the excitation zone [A] situated at the given depth, and signals acquired during the movements generated in response to the mechanical stress at at least the point [Bij] of the imaging zone [B] situated outside the excitation zone [A].

A method and a device for imaging a visco-elastic medium

The invention relates to a method for measuring a mean visco-elasticity value for a soft material. Said method using a single probe carrying at least one transducer comprises the steps of : a) inducing, in a constraint zone, at least one burst of mechanical vibrations in order to generate internal shear waves in the tissue propagating from said constraint zone into the tissue, bl) measuring, with said transducer, the transient tissue displacements in at least one first measurement zone in the tissue, said first measurement zone being located away from said constraint zone, c) estimating a mean visco-elasticity of the region of the tissue situated between the constraint zone and the first measurement zone from said measured transient tissue displacements of the tissue in the first measurement zone.

Method and device for measuring a mean value of visco-elasticity of a region of interest

We evaluated quantitative ultrasonic methods for assessment of carotid plaque content. In vitro measurements of fixed, carotid plaque specimens obtained by surgical endarterectomy were performed using a clinical Philips HDI 5000 imaging system connected to a radiofrequency (RF) signal-acquisition system. We acquired RF signals and grey-scale images from carotid specimens (n = 17) and a tissue-mimicking reference phantom. Imaged plaque sections were then classified according to histology. Parametric images were constructed from the integrated backscatter (IBS), and the midband, slope and intercept values of a straight-line fit to the apparent backscatter transfer function. Analysis was performed on 82 regions-of-interest (ROIs). The IBS values for collagen, lipid and hemorrhage plaques were 5.8 ± 5.4, 3.9 ± 3.7, 2.8 ± 2.2 dB, respectively. Midband and IBS parameter images exhibited good agreement in morphology with histology, whereas the slope and intercept parameter images were noisy. Mean IBS, midband, and grey-scale values of complex plaques were found to be statistically different (p < 0.05) from lipid, hemorrhage and fibrolipid plaques. The bias and limits of agreement (1.3 ± 4.9 dB) between the grey-scale and IBS methods, however, indicated that the two methods were not interchangeable. Results indicate necessary improvements, such as reduction of large measurement variances and identification of robust parameters, that will permit multiparametric characterization of carotid plaque under in vivo conditions. (E-mail: krwaters@boulder.nist.gov)

Claude Cohen-Bacrie

Papers

Elastic deformation detecting method and ultrasonograph

Time reversal operator decomposition with focused transmission and robustness to speckle noise: Application to microcalcification detection

A method and a device for imaging a visco-elastic medium

Method and device for measuring a mean value of visco-elasticity of a region of interest

Parametric analysis of carotid plaque using a clinical ultrasound imaging system.