Methods of ultrasonographic image data processing
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OBJECTIVE: Relations between measurable properties of B-mode ultrasound images of thyroid gland and clinical and laboratory findings in patients with chronic inflammation of thyroid gland were studied. METHODS: Data from 65 patients with lymphocytic thyroiditis (LT) and 38 control subjects were analysed. Raw values of individual B-mode image pixels and standard co-occurrence second-order texture features were selected as quantitative image features. Thyroid antibodies, thyrotropin level, thyroxine replacement therapy, and body mass index were used as clinical variables. RESULTS: In the LT group, significant differences (t-tests, p<0.05) in image features were found for body mass indices (BMI) under and over 25 kg.m(-2), for thyroxine replacement therapy, and for the presence and absence of thyroid antibodies. Forward stepwise multiple regression was performed for the clinical or laboratory values as dependent variables and image features as independent variables. The following correlations were found: 1. between BMI and four image features in the normal group; 2. between the dose of thyroxine replacement therapy and two of image features in the LT group; and 3. for the level of thyroid antibodies in the LT group: five image features have correlated with the level of anti-thyroglobulin and three image features with level of anti-thyroperoxidase. CONCLUSION: These findings suggest the possibility of using quantitative indicators of ultrasound image of thyroid gland as predictors of the presence or absence of thyroid antibodies in patient's blood or as an auxiliary tool for dose recommendation of thyroxine replacement therapy.
- MeSH
- autoimunitní tyreoiditida krev diagnostické zobrazování farmakoterapie imunologie MeSH
- autoprotilátky krev MeSH
- dospělí MeSH
- index tělesné hmotnosti MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- počítačové zpracování obrazu MeSH
- regresní analýza MeSH
- senioři MeSH
- thyreotropin krev MeSH
- thyroxin terapeutické užití MeSH
- ultrasonografie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- autoprotilátky MeSH
- thyreotropin MeSH
- thyroxin MeSH
A new method for two-dimensional deconvolution of medical ultrasonic images is presented. The spatial resolution of the deconvolved images is much higher compared to the common images of the fundamental and second harmonic. The deconvolution also results in a more distinct speckle pattern. Unlike the most published deconvolution algorithms for ultrasonic images, the presented technique can be implemented using currently available hardware in real-time imaging, with a rate up to 50 frames per second. This makes it attractive for application in the current ultrasound scanners. The algorithm is based on two-dimensional homomorphic deconvolution with simplified assumptions about the point spread function. Broadband radio frequency image data are deconvolved instead of common fundamental harmonic data. Thus, information of both the first and second harmonics is used. The method was validated on image data recorded from a tissue-mimicking phantom and on clinical image data.
- MeSH
- algoritmy * MeSH
- fantomy radiodiagnostické MeSH
- interpretace obrazu počítačem metody MeSH
- lidé MeSH
- počítačové zpracování signálu * MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- ukládání a vyhledávání informací metody MeSH
- ultrasonografie přístrojové vybavení metody MeSH
- vylepšení obrazu metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Three-dimensional (3D) sonography is the next logical step in diagnostic ultrasound examination. The true value of 3D ultrasonography, however, becomes evident only if 3D structures can be assessed without preconceptions ensuing from 2D interpretations. 3D ultrasonography can greatly improve our understanding of locomotor apparatus anatomy and pathology. The authors used spatial analysis to evaluate the data obtained by examination of patients with orthopedic diagnoses. The Voluson 530 MT and SONOReal system were used for examination. The Voluson permits a choice of either a 2D or a 3D imaging program for musculoskeletal system examination. The SONOReal, owing to a positional sensor of the probe, can be attached to any ultrasound transducer. In the period from 1990 to 2004, a total of 19 000 patients were examined by ultrasonography and, in 6 500 of them, the diagnosis was verified by another method, which showed a 99 % reliability of ultrasound examination. In 350 patients 2D imaging was followed by 3D examination; in 53 of them, 3D coronal and multiplanar imaging made the diagnosis based on 2D imaging more accurate and, in 12 patients, it provided new information on the patient's diagnosis. 3D reconstructions were made in 101 patients, of these 40 had been examined by other imaging methods (magnetic resonance, computer-assisted tomography) or arthroscopy. The results of examination showed a 100% correlation. Spatial reconstruction is based on the volume rendering method. This is an extension of the planar reconstruction method. Additional image processing techniques are used for a region of interest within a 3D volume data set. 3D ultrasound revealed a spatial relationship between lesions and their surfaces. The surface mode requires that the interface between tissues with different acoustic impedances should be a start line of 3D rendering. The acoustic threshold is a condition that restricts imaging circumstances in which surface rendering will be successful. Exploring 3D reconstructions with power Doppler scanning, which is more sensitive for tracking vessels, is a unique technique that can hardly be compared with any other imaging modality. 3D-volume imaging gives the examiner freedom to generate anatomical views from an infinite number of perspectives and allows us to explore anatomic relationships in the ways not available in any conventional 2D imaging. A spatial reconstruction presents a nearly perfect anatomical model. The possibility of storing volume data is considered a further progressive trend. It greatly contributes to enhancement of the scope of follow-up examinations, permits comparisons of expert conclusions and can serve educational purposes. The digital technology offers various networking solutions and plays a role in the development of 3D telemedicine. Although the diagnostic efficacy of 3D imaging is not greatly enhanced when compared with a 2D examination done by a well-trained specialist, the features of coronary sections and spatial reconstructions represent great progress of this imaging technology.
- MeSH
- lidé MeSH
- muskuloskeletální systém diagnostické zobrazování MeSH
- počítačové zpracování obrazu MeSH
- ultrasonografie MeSH
- zobrazování trojrozměrné * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The contribution presents some results obtained on the way to checking (and partly complementing) the standard reconstruction procedures in USCT by wave-equation based simulations. Mathematical models emerging from the transparent physical background for both the surrounding fluid and the object tissue are presented, followed by the present results of developing a realistic original finite-element-method based simulation. With respect to the need of comparison with the calibration measurements, a preliminary optimization of initial guesses to boundary conditions at the transducer array is discussed, based on a point-source model. The computational requirements of the procedures are also mentioned together with concrete examples of achieved results.
This article describes a novel method for highly accurate and effective localization of the transverse section of the carotis comunis artery in ultrasound images. The method has a high success rate, approximately 97%. Unlike analytical methods based on geometric descriptions of the object sought, the method proposed here can cover a large area of shape variation of the artery under study, which normally occurs during examinations as a result of the pressure on the examined tissue, tilt of the probe, setup of the sonographic device, and other factors. This method shows great promise in automating the process of determining circulatory system parameters in the non-invasive clinical diagnostics of cardiovascular diseases. The method employs a Viola-Jones detector that has been specially adapted for efficient detection of transverse sections of the carotid artery. This algorithm is trained on a set of labeled images using the AdaBoost algorithm, Haar-like features and the Matthews coefficient. The training algorithm of the artery detector was modified using evolutionary algorithms. The method for training a cascade of classifiers achieves on a small number of positive and negative training data samples (about 500 images) a high success rate in a computational time that allows implementation of the detector in real time. Testing was performed on images of different patients for whom different ultrasonic instruments were used under different conditions (settings) so that the algorithm developed is applicable in general radiologic practice.
- Klíčová slova
- B-mode ultrasound, Carotid artery, Evolutionary algorithms, Image processing, Transverse section, Viola-Jones detector,
- MeSH
- algoritmy * MeSH
- arteriae carotides diagnostické zobrazování MeSH
- interpretace obrazu počítačem metody MeSH
- lidé MeSH
- počítačové systémy MeSH
- reprodukovatelnost výsledků MeSH
- rozpoznávání automatizované metody MeSH
- senzitivita a specificita MeSH
- software MeSH
- ultrasonografie metody MeSH
- umělá inteligence MeSH
- vylepšení obrazu metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A new approach to 2-D blind deconvolution of ultrasonic images in a Bayesian framework is presented. The radio-frequency image data are modeled as a convolution of the point-spread function and the tissue function, with additive white noise. The deconvolution algorithm is derived from statistical assumptions about the tissue function, the point-spread function, and the noise. It is solved as an iterative optimization problem. In each iteration, additional constraints are applied as a projection operator to further stabilize the process. The proposed method is an extension of the homomorphic deconvolution, which is used here only to compute the initial estimate of the point-spread function. Homomorphic deconvolution is based on the assumption that the point-spread function and the tissue function lie in different bands of the cepstrum domain, which is not completely true. This limiting constraint is relaxed in the subsequent iterative deconvolution. The deconvolution is applied globally to the complete radiofrequency image data. Thus, only the global part of the point-spread function is considered. This approach, together with the need for only a few iterations, makes the deconvolution potentially useful for real-time applications. Tests on phantom and clinical images have shown that the deconvolution gives stable results of clearly higher spatial resolution and better defined tissue structures than in the input images and than the results of the homomorphic deconvolution alone.
- MeSH
- algoritmy * MeSH
- Bayesova věta MeSH
- interpretace obrazu počítačem metody MeSH
- reprodukovatelnost výsledků MeSH
- rozpoznávání automatizované metody MeSH
- senzitivita a specificita MeSH
- ultrasonografie metody MeSH
- umělá inteligence * MeSH
- vylepšení obrazu metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This paper presents a system for correcting motion influences in time-dependent 2D contrast-enhanced ultrasound (CEUS) images to assess tissue perfusion characteristics. The system consists of a semi-automatic frame selection method to find images with out-of-plane motion as well as a method for automatic motion compensation. Translational and non-rigid motion compensation is applied by introducing a temporal continuity assumption. A study consisting of 40 clinical datasets was conducted to compare the perfusion with simulated perfusion using pharmacokinetic modeling. Overall, the proposed approach decreased the mean average difference between the measured perfusion and the pharmacokinetic model estimation. It was non-inferior for three out of four patient cohorts to a manual approach and reduced the analysis time by 41% compared to manual processing.
- Klíčová slova
- CEUS, Contrast-enhanced ultrasound, Motion analysis, Motion compensation, Perfusion, Perfusion modeling, Registration, Ultrasonography,
- MeSH
- břicho diagnostické zobrazování MeSH
- Crohnova nemoc diagnostické zobrazování MeSH
- cystická fibróza diagnostické zobrazování MeSH
- databáze faktografické * MeSH
- interpretace obrazu počítačem metody MeSH
- kontrastní látky aplikace a dávkování MeSH
- lidé MeSH
- pohyb těles MeSH
- ultrasonografie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kontrastní látky MeSH
Wavelet transform (WT) is a commonly used method for noise suppression and feature extraction from biomedical images. The selection of WT system settings significantly affects the efficiency of denoising procedure. This comparative study analyzed the efficacy of the proposed WT system on real 292 ultrasound images from several areas of interest. The study investigates the performance of the system for different scaling functions of two basic wavelet bases, Daubechies and Symlets, and their efficiency on images artificially corrupted by three kinds of noise. To evaluate our extensive analysis, we used objective metrics, namely structural similarity index (SSIM), correlation coefficient, mean squared error (MSE), peak signal-to-noise ratio (PSNR) and universal image quality index (Q-index). Moreover, this study includes clinical insights on selected filtration outcomes provided by clinical experts. The results show that the efficiency of the filtration strongly depends on the specific wavelet system setting, type of ultrasound data, and the noise present. The findings presented may provide a useful guideline for researchers, software developers, and clinical professionals to obtain high quality images.
A new signal model and processing method for quantitative ultrasound perfusion analysis is presented, called bolus-and-burst. The method has the potential to provide absolute values of blood flow, blood volume, and mean transit time. Furthermore, it provides an estimate of the local arterial input function which characterizes the arterial tree, allowing accurate estimation of the bolus arrival time. The method combines two approaches to ultrasound perfusion analysis: bolus-tracking and burst-replenishment. A pharmacokinetic model based on the concept of arterial input functions and tissue residue functions is used to model both the bolus and replenishment parts of the recording. The pharmacokinetic model is fitted to the data using blind deconvolution. A preliminary assessment of the new perfusion-analysis method is presented on clinical recordings.
- MeSH
- algoritmy MeSH
- arteria iliaca diagnostické zobrazování MeSH
- Crohnova nemoc diagnostické zobrazování MeSH
- databáze faktografické MeSH
- diagnostické zobrazování MeSH
- farmakokinetika MeSH
- hemodynamika MeSH
- kontrastní látky farmakokinetika MeSH
- lidé MeSH
- perfuze metody MeSH
- počítačové zpracování signálu * MeSH
- teoretické modely * MeSH
- ultrasonografie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kontrastní látky MeSH
OBJECTIVES: To describe imaging modalities for diagnosing and monitoring of patients with idiopathic inflammatory myopathies. METHODS: A detailed literature search summarising recent data documenting the contribution of different imaging techniques to current management of idiopathic inflammatory myopathies was performed. RESULTS: An overview of methods most frequently used for evaluation of inflammatory myopathies and the description of their role in the diagnostic and monitoring process is presented. CONCLUSIONS: MRI is currently the most useful method capable of demonstrating both inflammatory and post-inflammatory changes in the muscles and surrounding soft tissue. Several studies have documented potential usefulness of other imaging techniques, such as ultrasonography, positron emission tomography, scintigraphy, and dual-energy x-ray absorptiometry.
- MeSH
- absorpční fotometrie MeSH
- kosterní svaly diagnostické zobrazování patofyziologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- myozitida diagnostické zobrazování patofyziologie terapie MeSH
- pozitronová emisní tomografie MeSH
- prediktivní hodnota testů MeSH
- prognóza MeSH
- reprodukovatelnost výsledků MeSH
- revmatologie metody MeSH
- stupeň závažnosti nemoci MeSH
- ultrasonografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
