Grayscale Changes Research Articles

OC27.07: New horizons about the diagnosis of breast masses by SonoLiverR CAP imaging analysis software

Study the application of new SonoLiverR CAP pseudo-color imaging analysis software in the breast masses, and discuss the new method about differentiation of benign and malignant breast tumor. This group including 64 masses from November 2006 to May 2009 were examined by contrast-enhanced ultrasound (CEUS) and SonoLiverR CAP pseudo-color imaging analysis which has been confirmed by surgery and pathology. We use ROC curve to assess its diagnostic performance. In 64 masses which studied by the new SonoLiverR CAP pseudo-color imaging analysis software, 37 masses with purple-red region which meant high-enhanced and 27 masses with purple-blue region which meant low-enhanced. 76.5% malignant masses were showed high-enhanced but only 26.9% in benign ones. Inflammation with necrosis of the breast were all high-enhanced. A great deal of those high-enhanced masses were malignant, and few were benign. The malignant masses of high-enhanced were irregular in whole, patching sometimes (84.6%); benign ones were speckle and streak (85.7%). Measurement of peak intensity about the percentage of high-enhanced purple areas in the whole tumor region: malignant (58.39 + 18.20)%, benign (32.78 + 16.30)%, (P < 0.05). The area under ROC curve was 0.8235. SonoLiverR CAP imaging analysis software is different from previous analysis, the gray scale changes can be converted into color changes, the demonstration of dynamic vascular model which coded by pseudo-color is clearly, intuitive, simple and will reduce the pressure on doctors. Opened up a new vision about the diagnosis of breast masses.

Unified Direct Visual Tracking of Rigid and Deformable Surfaces Under Generic Illumination Changes in Grayscale and Color Images

The fundamental task of visual tracking is considered in this work as an incremental direct image registration problem. Direct methods refer to those that exploit the pixel intensities without resorting to image features. We propose new transformation models and optimization methods for directly and robustly registering images (including color ones) of rigid and deformable objects, all in a unified manner. We also show that widely adopted models are in fact particular cases of the proposed ones. Indeed, the proposed general models combine various classes of image warps and ensure robustness to generic lighting changes. Finally, the proposed optimization method together with the exploitation of all possible image information allow the algorithm to achieve high levels of accuracy. Extensive experiments are reported to demonstrate that visual tracking can indeed be highly accurate and robust despite deforming objects and severe illumination changes.

Accuracy of gray-scale coding in lung sound mapping

Stethoscope evaluation of the lungs is widely accepted and practiced; however, there are some widely recognized, major limitations with its use. A safe device that helped solve these limitations by translating sound into objective, quantifiable images would have clinical utility. Translating lung sounds into quantifiable images in which regional differences or asymmetry in intensities of breath sounds are presented as gradients in gray-scale is not a trivial process. Healthy lungs and lung pathology are characterized by different patterns of regional breath sound distribution and, therefore, the accuracy of mapping gray-scale images must be ensured in a controlled systematic fashion prior to clinical use of such a technique. Vibration response imaging (VRI) maps lung sounds from 40 sensors to a two-dimensional gray-scale image. To assess mapping accuracy, a simulated lung sound map with uniform signals was compared to modified maps where sound signals were reduced (1–3 db) at one sensor. Also, 8 readers evaluated the gray-scale images. The computer algorithm accurately displayed gray-scale coding changes in correct locations in 97% of images. There was 95 ± 4% accuracy rate by readers to correctly identify gray-scale changes. In addition, quantitative data at different stages of signal processing were investigated in a LSM of a subject with asthma. Signal processing was 97% accurate overall in that the gray-scale values from which the image was derived corresponded with intensity values from recorded signals. These results suggest VRI accurately maps acoustic signals to a gray-scale image and that trained readers can detect small changes.

Use of hemicellulase in sequence with hydrogen peroxide and laccase for improvement of teak veneer surface color

Teak veneer was treated with a commercial hemicellulase from Thermomyces lanuginosus in sequence with hydrogen peroxide or a hydrogen peroxide-laccase mixture to improve the veneer surface color and at the same time to reduce the necessary amount of hydrogen peroxide. The removal of a small portion of hemicellulose from the teak veneer surface could be carried out after treatment with the hemicellulase preparation as 0.05 xylanase unit/ml for 30 min. The veneer samples immediately after the hemicellulase treatment were subjected to the designated concentration of hydrogen peroxide or hydrogen peroxide-laccase mixture at 60°C at pH 6.5 for 4 h. The changes in veneer color were measured by using imaging technology as percentage change in gray scale. A treatment combination of hemicellulase containing xylanase, hydrogen peroxide, and laccase yielded a color improvement close to that achieved using 20% hydrogen peroxide. The results showed that hemicellulase pretreatment could improve the bleachability of teak veneer surfaces treated with hydrogen peroxide or hydrogen peroxide-laccase mixture.

Lipreading With Local Spatiotemporal Descriptors

Visual speech information plays an important role in lipreading under noisy conditions or for listeners with a hearing impairment. In this paper, we present local spatiotemporal descriptors to represent and recognize spoken isolated phrases based solely on visual input. Spatiotemporal local binary patterns extracted from mouth regions are used for describing isolated phrase sequences. In our experiments with 817 sequences from ten phrases and 20 speakers, promising accuracies of 62% and 70% were obtained in speaker-independent and speaker-dependent recognition, respectively. In comparison with other methods on AVLetters database, the accuracy, 62.8%, of our method clearly outperforms the others. Analysis of the confusion matrix for 26 English letters shows the good clustering characteristics of visemes for the proposed descriptors. The advantages of our approach include local processing and robustness to monotonic gray-scale changes. Moreover, no error prone segmentation of moving lips is needed.

Determination of erythrocyte flow velocity by dynamic grey scale measurement using off-line image analysis

Determination of erythrocyte flow velocity is an important parameter for microcirculatory research. We established an off-line method for determining erythrocyte velocity in microcirculation by computer- ized dynamic grey scale analysis. In principle, the method is based on the dual-slit photometric technique (1), and updated by software image analysis. We have applied high speed video recorder (FASTCAM- ultima APX, Photron, San Diego, CA) to capture digital images for mesentery microvessels in rat and rabbit since 2004. Each series of images during 10 seconds is captured at a speed of 2000 frames/s (fps) and is composed of images of 704 × 576 pixels with 256 grey levels. The video recording is converted to AVI format required by the software of ImagePro Plus (versions 4.5 or 5.0). The video is then inves- tigated frame by frame with the help of the Sequencer Toolbar in the menu of ImagePro Plus. The criterion for selecting an investigative segment in a capillary is that the erythrocyte flow keeps smooth and steady for 10 seconds at least. A reference line perpendicular to the axis of the capillary is setup to show the grey scale distribution along the radial line in the first frame of image. Then, a down-stream measuring line perpendicular to the axis of the capillary is setup with a distance about 10 µm apart from the reference line. The dynamic grey scale changes at the measuring line in the subsequent images are monitored frame by frame and the changes are compared with the grey scale distribution at the reference line in the first image (Figs 1 and 2). When the most grey scale with the reference distribution is detected, the time interval for erythrocytes flowing from the reference line in the first frame to the measuring line in the matchable frame can be figured out by multiplying the frame difference by the duration between each frame. The erythrocyte velocity can be easily calculated by dividing the distance between the reference line and the measuring line by the time interval (Fig. 2).

Diagnostic accuracy of power Doppler ultrasound in patients with chronic tennis elbow

Objective:To determine the diagnostic accuracy of power Doppler and grey scale ultrasonography, assess the relationship between severity measures and neovascularity, and describe the intra-tendon distribution of neovascularity in chronic tennis...

Dynamic Texture Recognition Using Local Binary Patterns with an Application to Facial Expressions

Dynamic texture (DT) is an extension of texture to the temporal domain. Description and recognition of DTs have attracted growing attention. In this paper, a novel approach for recognizing DTs is proposed and its simplifications and extensions to facial image analysis are also considered. First, the textures are modeled with volume local binary patterns (VLBP), which are an extension of the LBP operator widely used in ordinary texture analysis, combining motion and appearance. To make the approach computationally simple and easy to extend, only the co-occurrences of the local binary patterns on three orthogonal planes (LBP-TOP) are then considered. A block-based method is also proposed to deal with specific dynamic events such as facial expressions in which local information and its spatial locations should also be taken into account. In experiments with two DT databases, DynTex and Massachusetts Institute of Technology (MIT), both the VLBP and LBP-TOP clearly outperformed the earlier approaches. The proposed block-based method was evaluated with the Cohn-Kanade facial expression database with excellent results. The advantages of our approach include local processing, robustness to monotonic gray-scale changes, and simple computation.

A Comparison Between Urethane and Gel Test Objects for Ultrasound Imaging Performance Testing

Both urethane and gel based test objects are widely used for ultrasound imaging performance testing. Urethane has a lower sound propagation speed, resulting in defocusing of the ultrasound beam. The aims of this work were to compare the ability of urethane and gel test objects in demonstrating the deliberate de-optimization of an ultrasound scanner via resolution and dynamic range changes. Images were captured from two test objects using four scanners with optimized and de-optimized settings for focusing and dynamic range. The images were analysed for resolution, grey-scale target contrast and visibility, and high contrast target visibility and the significance of differences between optimized and de-optimized settings were assessed. Overall, the urethane test object demonstrated more significant changes (15; 9 for gel test object) with the lateral resolution changing more often than the other image qualities. If the beam profile or grey scale changes, we are more likely to see a change in resolution measurement and the urethane test object is more likely to demonstrate these changes.

1152: Color Doppler ultrasound of major salivary glands

Color Doppler ultrasound (CDU) is an important imaging technique for analyzing the vascularity of the salivary glands and, in conjunction with gray-scale imaging, can be used to characterize some pathologic conditions. Patients with Sjogren’s syndrome may or may not show parenchymal changes on high-resolution gray-scale ultrasound (US). Gray-scale changes mainly consist of a decrease of parenchymal echogenicity up to a total derangement of parenchymal texture, cyst-like ectasia of peripheral ducts, undefined margins and decreased volume of the gland. CDU show a higher number of color flow signals (CFS) in all heterogeneous glands than in normal glands. The hypervascularity is generally diffuse and can be subjectively graded (e.g., minimal, ± or +; intermediate, ++; or profuse, +++ or ++++). Patients with salivary gland involvement in sarcoidosis had marked parotid swelling and a high grade of parenchymal heterogeneity on US.CDU shows diffuse hypervascularity of the glands similar to that seen in Sjogren’s disease. In chronic sclerosing sialadenitis the most common US appearances are the diffuse cirrhotic-like patterns. The involved gland shows prominent vascularity (++–+++) on CDU, with no mass effect or obvious displacement of the vessels. Both benign and malignant tumors have a higher grade of vascularity than the surrounding salivary parenchyma. Generally, malignant parotid tumors demonstrate a higher degree of tumor vascularization (profuse or intermediate) and higher peak systolic velocities (PSV) than benign tumors. Pleomorphic adenomas are oval hypoechoic lesions. Most had intermediate grade of vascularity and a peripheral basket-like pattern consisting of a fine vascular network surrounding the nodule. Spectral Doppler analysis (SDA) shows a wide range of resistivity index (RI) values (0.6 to 1.0), and a PSV below 50 cm s. Adenolymphomas are well-demarcated tumors, frequently associated with one or more cystic components and posterior enhancement. The larger the lesion, the more predominant the cystic portion. CDU depicts a hilar disposition of CFS with centrifugal distribution through one or more vascular pedicles in a relatively regular pattern. The RI and PSV are not significantly different from those in pleomorphic adenoma. Non-Hodgkin’s lymphomas appeared on US as single or occasionally multiple hypoechoic nodules in the parotid gland, similar to the pleomorphic adenomas, and have feeding and draining vessels that enter or leave and branch into the nodule through a centrally located pedicle, although a real hilum is not visible on gray-scale US. CDU shows profuse (graded +++ or ++++) vascularity. The accuracy of evaluating parotid tumors by gray-scale US has been reported to range from 78% to 90% for benign lesions and lower for malignant tumors (57% to 67%). Estimating the histologic type of a parotid tumor has been reported to have an accuracy of 60%. Fine needle aspiration (FNA) has a limited role in the evaluation of salivary tumors. However, FNA and core needle biopsy are of great aid in the evaluation of inflammatory or tumor-like conditions of salivary glands. CDU-guided biopsy with sampling in different locations of the enlarged salivary gland can provide sufficient diagnostic information from the histologic study to prevent sampling errors of the cytologic study. CDU shows promise as an adjunct to gray-scale US in the differential diagnosis of salivary pathologies.

Nanoparticles as image enhancing agents for ultrasonography

Nanoparticles have drawn great attention as targeted imaging and/or therapeutic agents. The small size of the nanoparticles allows them to target cells that are beyond capillary vasculature, such as cancer cells. We investigated the effect of solid nanoparticles for enhancing ultrasonic grey scale images in tissue phantoms and mouse livers in vivo. Silica nanospheres (100 nm) were dispersed in agarose at 1–2.5% mass concentration and imaged by a high-resolution ultrasound imaging system (transducer centre frequency: 30 MHz). Polystyrene particles of different sizes (500–3000 nm) and concentrations (0.13–0.75% mass) were similarly dispersed in agarose and imaged. Mice were injected intravenously with nanoparticle suspensions in saline. B-mode images of the livers were acquired at different time points after particle injection. An automated computer program was used to quantify the grey scale changes. Ultrasonic reflections were observed from nanoparticle suspensions in agarose gels. The image brightness, i.e., mean grey scale level, increased with particle size and concentration. The mean grey scale of mouse livers also increased following particle administration. These results indicated that it is feasible to use solid nanoparticles as contrast enhancing agents for ultrasonic imaging.

Assessment of enthesitis in ankylosing spondylitis by power Doppler ultrasonography

To evaluate the relationship between power Doppler ultrasonography (PDUS) assessment and clinical variables including enthesitis index, pain threshold and disease activity parameters, and to document grey-scale US findings of the 13 entheses examined. A total of 390 entheses were examined in thirty patients with AS, and clinical variables of the Maastricht Ankylosing Spondylitis Enthesitis Index (MASES), anthropometric measurements, disease activity and functional parameters were documented. A total MASES score by palpation (t-PS) and algometric pressure pain threshold (t-PPT) was obtained. Grey scale and PDUS examination of 13 entheses were performed. Grey-scale changes such as altered tendon echogenity, calcification, cortical reactive changes and bursitis were noted, and flow on PDUS was graded semi-quantitatively. Cumulative power Doppler (t-PDS) score significantly correlated with t-PS and t-PPT. Ultimate correlations were found between power Doppler scores and pain, disease activity and disability parameters. Changes in grey scale combined with PDUS were more prevalent in lower-extremity entheses. The intraobserver agreement of flow signal grading was excellent (kappa = 0.82). Clinical and sonographic results were concordant for three regions, but were discordant for four regions where tenderness was accepted as the sole clinical manifestation of enthesis. Pain or tenderness is associated with increased vascularity of entheses. Power Doppler US examination of the entheses may be useful and complementary to the clinical evaluation, and further research is needed to assess its role in diagnosis and follow-up of disease course.

Real-time monitoring of ultrasound imaging of clinical high intensity focused ultrasound (HIFU) exposures

Currently, many clinical devices use the change in gray scale seen on a real-time ultrasound image for the assessment of the success of HIFU treatment. It has been shown previously that, for a single HIFU lesion, the presence of gray-scale change was indicative of successful ablation in 100% of cases for 1.6-MHz beams, and in 90% of cases for 0.8-MHz exposures. The absence of gray-scale change was a reliable indicator of lack of ablative damage only for 0.8-MHz exposures (80%); in 80% of exposures using 1.6-MHz beams there was a lesion even in the absence of gray-scale change. This study has been extended to more realistic clinical treatment protocols. The image appearance has been studied for the different volume ablation techniques that are used in the treatment of liver and kidney cancer. The results will be presented.

Understanding and predicting electronic vibration stress using ultrasound excitation, thermal profiling, and neural network modeling

Vibration stress is a major source for failure of electronics components. In this study, we used an ultrasonic/infrared system to generate vertical vibration of a microprocessor on a printed circuit board, in order to study the impact of short burst high load vibration stress on component integrity. The objectives of this research were to (1) understand the impact of vibration on electronic components under ultrasound excitation; (2) model the thermal profile presented under vibration stress; and (3) predict stress level given a thermal profile of an electronic component. Research tasks included: (1) retrofit of current ultrasonic/infrared nondestructive testing system with sensory devices for temperature readings; (2) design of software tool to process images acquired from the ultrasonic/infrared system; (3) developing hypotheses and conducting experiments; and (4) modeling and evaluation of electronic vibration stress levels using a neural network model. Results suggest that (1) an ultrasonic/infrared system can be used to mimic short burst high vibration loads for electronics components; (2) temperature readings for electronic components under vibration stress are consistent and repeatable; (3) as stress load and excitation time increase, temperature differences also increase; (4) components that are subjected to a relatively high pre-stress load, followed by a normal operating load, have a higher heating rate and lower cooling rate. These findings are based on grayscale changes in images captured during experimentation. Discriminating variables and a neural network model were designed to predict stress levels given temperature and/or grayscale readings. Results suggest a 15.3% error when using grayscale change rate and 12.8% error when using average heating rate within the neural network model. Data were obtained from a high stress point (the corner) of the chip.

Grey Scale and Power Doppler Sonographic Changes Induced by Intraarticular Steroid Injection Treatment

Grey Scale and Power Doppler Sonographic Changes Induced by Intraarticular Steroid Injection Treatment

Intravascular ultrasound molecular imaging of atheroma components in vivo

ObjectivesOur purpose was to quantitate and confirm specific echogenic immunoliposome (ELIP) atheroma component enhancement in vivo. BackgroundTargeted ELIPs for ultrasonic detection and staging of active molecular components of endothelium and atheroma have been developed. MethodsIn Yucatan miniswine, the endothelium was injured from one femoral and one carotid artery, and animals were fed a high-cholesterol diet for two months to create various stages of atheroma. Arteries were imaged with intravascular ultrasound (IVUS) 5 and 10 min after ELIP injection (5-mg dose). Anti-intercellular adhesion molecule-1 (ICAM-1), anti-vascular cell adhesion molecule-1 (VCAM-1), anti-fibrin, anti-fibrinogen, and anti-tissue factor (TF) conjugated ELIPs were used, and immunohistochemistry (IHC) confirmed the presence or absence of molecular expression. Two blinded observers determined if each segment was enhanced by ELIP. Three-dimensional image reconstruction and videodensitometric analysis determined the mean gray-scale (MGS) change of the luminal border. ResultsTo determine endothelial injury component enhancement, anti-fibrinogen ELIP enhanced exposed fibrin in all arteries (MGS increased 22 ± 5%; 6 arteries; 2 animals). To determine enhancement of molecular components in atherosclerotic arteries, observers detected enhancement 5 min after anti-VCAM, anti-ICAM, anti-TF, anti-fibrin, and anti-fibrinogen conjugated ELIPs. Furthermore, ELIP enhanced atheroma MGS by 39 ± 18% (n = 8). The IHC staining confirmed the expression of respective molecular targets in all enhanced segments. ConclusionsIt was shown that ELIPs specifically enhance endothelial injury/atheroma components. This allows better characterization of the type and extent of active atheroma components and may allow more directed therapy.

Monitoring of Interstitial Laser Thermotherapy with Heat-sensitive Colour Subtraction Magnetic Resonance Imaging: Calibration with Absolute Tissue Temperature and Correlation with Predicted Lesion Size

. Magnetic resonance imaging (MR) is the most sensitive modality for monitoring interstitial thermotherapy (ILT). A real-time pulse sequence that assigns a colour spectrum to grey-scale changes could potentially increase the accuracy of MR-guided thermal surgery. This study aimed to calibrate this sequence with tissue temperature and then to determine whether it could be used to predict accurately the extent of tissue necrosis produced during the formation of a thermal lesion.

Conventional and hypobaric activation of an ultrasound contrast agent

Hypobaric activation is a new injection technique for use with the contrast agent EchoGen® and, in this study, the agent’s ability to produce parenchymal enhancement in vivo, with and without prior hypobaric activation, was investigated. Injections, ranging in dose from 0.05 to 0.5 mL/kg, were administrated through a peripheral vein to eight woodchucks with multiple hepatomas. At the 0.10 mL/kg dose level, seven of eight injections following hypobaric activation (88%) resulted in definite parenchymal enhancement. Conversely, dosages of 0.10 mL/kg without prior hypobaric activation produced no grey-scale changes. Only at the 0.4 and 0.5 mL/kg dosage level did the conventional administration technique obtain similar results (4 of 5 injections increased the echogenicity for a 0.4 mL/kg dose). These differences were statistically significant ( p = 0.031). In vitro experiments were conducted to establish the physical mechanisms behind hypobaric activation. Relative measurements of contrast microbubble sizes were performed with a phase Doppler particle analyzer after hypobaric and after conventional (bolus) activation. Hypobaric activation produced approximately 20 times more microbubbles per unit volume than the conventional method. In conclusion, this investigation has demonstrated the benefits of prior hypobaric activation when performing in vivo contrast studies with EchoGen® and determined the physical mechanisms behind this new injection technique. Hypobaric activation of EchoGen® increases contrast enhancement and reduces dose size.

Interpretation of periapical lesions using RadioVisioGraphy

Density and gray-scale changes in radiographs are important visual features the clinician uses to evaluate changes in bone pattern. With the advent of a new direct digital radiology system, RadioVisioGraphy (RVG), the controlled adjustment of contrast is now possible. The purpose of this study was to compare RVG's diagnostic potential for detecting periapical lesions with that of conventional radiography. Lesions were created in human cadaver specimens and radiographed conventionally and with RVG. Images were evaluated by three endodontists. Results were: (a) when no lesion existed, conventional radiographs were more diagnostic than RVG at a significance level at p < or = 0.05; (b) when lesions were enlarged to involve lamina dura and medullary bone, RVG was superior at p < or = 0.05; and (c) no difference was found between conventional radiography and RVG when the lesion involved cortical bone.

Blood Flow Determinations Utilizing Digital Densitometry

A method of obtaining relative and absolute blood flow measurements from digital densitometry was evaluated with a simulated vessel phantom and a hydrodynamic model. A digital vascular imaging system capable of acquisition in 5122 and 10242 mode was used. Relative and absolute blood flow were measured using parameters derived from the densitometric curve. Since application of densitometric data to absolute flow measurements requires the vessel diameter, an algorithm for vessel size determination was created. Gray scale changes were demonstrated to be linearly related to contrast concentration. The variance of vessel size determination was significantly different in all combinations of 10242 and 5122 imaging with 15 cm or 35 cm field size. The error in vessel size determination was significantly less using the larger 10242 matrix and the smaller 15 cm image intensifier field size, as shown by the smaller variance. In relative flow determinations, there was good correlation between the flow and four parameters of the densitometric curve with no significant differences between 5122 and 10242 imaging. Absolute flow determinations had slightly lower correlation to actual flow but were not significantly different from relative flow determinations. Relative and absolute blood flow determinations can be performed adequately with either 5122 or 10242 imaging. The increased accuracy in vessel size determination with 10242 imaging makes this high resolution system potentially preferable to determine absolute blood flow.