Bioacoustics Research Lab
University of Illinois at Urbana-Champaign | Department of Electrical and Computer Engineering | Department of Bioengineering
Department of Statistics | Coordinated Science Laboratory | Beckman Institute | Food Science and Human Nutrition | Division of Nutritional Sciences | College of Engineering
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William D. O'Brien, Jr. publications:

Michael L. Oelze publications:

Aiguo Han publications:

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Title Advanced ultrasonic imaging techniques for breast cancer research.
Author Insana MF, Oelze ML.
Journal Book Chapter
Volume
Year 2006
Abstract Introduction - The goal of cancer imaging is to exploit disease-specific object contrast mechanisms that provide very specific information about cellular structure and function to help diagnose and manage diseases and to develop tools for scientific investigation. This chapter reviews several ultrasonic methods for obtaining detailed histological descriptions of mammary tissue noninvasively that are related directly to tumor growth. Ultrasonic imaging (sonography) is now routinely applied in a clinical setting as an adjunct to mammography and the physical examination. Its role is primarily to differentiate solid tumors from cysts and to guide needle and surgical excision biopsies. Tumors larger than 8 mm are readily detected as hypoechoic (lower echo strength) regions. Unfortunately sonographic features are frequency nonspecific; the appearance of benign masses, such as fibrocystic lesions and fibroademomas, is often similar to that of malignant lesions, such as infiltrating ductal carcinoma (IDC) and infiltrating lobular carcinoma (ILC). Sonography is very useful for locating lesions and ruling out cysts, although the definitive differential diagnosis requires pathological analysis of biopsy samples. A needle biopsy is minimally invasive but suffers from sampling errors; small lesions can be easily missed. Surgical biopsies remove more tissue, reducing sampling errors, but introduce the risks and expenses associated with any surgical procedure. Surgical biopsy is a hybrid diagnostic-therapeutic procedure, so we would like to use it only when we’re reasonably confident that cancer is present. Our goal is to increase the diagnostic information provided by ultrasound scans safely and at low cost, so that frequent serial imaging of patients at risk can be applied to reduce the number of questionable biopsies without sacrificing diagnostic performance. Such methods can be used periodically for the initial diagnosis and regularly for monitoring a patient’s response to treatment. Working against our proposed expanded use of ultrasound is the complexity and diversity of breast cancer and natural inter-patient variability. Since histopathology is how cancer is defined, it is completely accurate at one instant of time except for human error. Radiological procedures are strong at detecting and localizing lesions but are rarely used to classify disease since images only describe a small subset of the total histological feature space. Thus it is unlikely that any one diagnostic test can reliably detect and classify breast cancers in all patients. Identifying diverse disease processes is improved by increasing the feature space for classification. The best strategy is to provide decision makers with several independent features related uniquely to tissue properties that span the range of disease phenotypes. A simple example is the current combination of mammography and palpation. Mammography is most accurate for detecting early tumors that produce microcalcifications. Manual palpation exposes tumors that become mechanically stiff. Insofar as the effects are uncorrelated, their combination more effectively aids diagnosis than each applied individually. Even recent molecular imaging methods that seek to reveal and treat suspicious regions based on high angiogenic activity can fail when used alone [45]. Promising new approaches strive to recognize tumors that express a broad range of angiogenic factors and related molecular signals. Like other researchers, we have turned to the molecular biology of cancer to find hallmark features for imaging. From the literature of the past two decades, a richly detailed picture of the biology of breast cancer is emerging [16,61,78]. It is clear that the initiation, rate of progression, and occurrence of malignant transformation are determined by a combination of genetic and epigenetic factors; the later encompassed by the term “cellular microenvironment”. Many of these discoveries suggest new opportunities for combined cancer imaging and treatment that promise increased sensitivity and specificity. One manifestation is the new field of molecular imaging [4, 60, 79]. Most molecular imaging approaches include development of blood-born particles, known as probes or beacons, with biologically active surfaces. These particles target disease-specific molecular sites in the body and emit or reflect energy that can be sensed by current imaging modalities [1, 13, 50]. The development of targeted contrast agents is largely a chemical synthesis problem; one of being able to functionalize particle surfaces so they remain stably active while circulating in the blood stream seeking their targets. Our approach is to image histological features of breast tissues that influence the cellular microenvironment (defined below) without contrast enhancement through the unique capabilities of ultrasound. Ultrasound is highly sensitive to subtle variations in the mechanical properties of tissues at many scales that often change as the composition and distribution of cells is modified by disease. To model sound tissue interactions, tissues are viewed from the materials science viewpoint as a viscoelastic continuum (think of gelatin) in which compressional sound waves travel. Within glandular tissues, cells, connective tissues and the microvasculature reflect a small amount of the sound energy back to the detector. Because the wavelength of diagnostic ultrasound (150 ¹m) is about 300 times longer than the wavelength of visible light (500 nm), the spatial resolution possible for ultrasound is far below optical microscopy. Nevertheless, lower attenuation allows ultrasound to penetrate deeper into the body than light and therefore it is unnecessary to extract tissue samples for analysis. Rather than resolving individual structures, a statistical ultrasonic analysis examines the statistical properties of echo signals to estimate average properties of tissue structures at the scale of the cell. For example, we can create parametric ultrasound images where the image pixels represent the average size of scatterers. Using pre-image echo signals from clinical instruments and advanced signal processing methods, parametric ultrasound images quantify structural features of fibrotic tissues and regions of cellular hypertrophy and hyperplasia with the spatial resolution of sonography. In this application, ultrasound is applied to describe microscopic mechanical properties of tissues. We can also use ultrasound to track tissue motion and thereby observe the macroscopic mechanical properties of tissues using the techniques of elasticity imaging. As we show below, cancer modifies how cells are connected to one another over a long distance, a feature of the disease that is often missed by histopathology. Ultrasound can detect the spatial distribution of tiny local movements caused when tissues are gently squeezed to estimate viscoelastic properties with the spatial resolution of sonography. Elasticity imaging can describe desmoplasia, edema, and other processes that stiffen tissue. It also describes ultrastructural changes to the intra- and inter-lobular stroma that alter how water is attracted to the extracellular matrix and how collagen fibers are cross linked. Combining the microscopic and macroscopic ultrasonic features, we gain new perspectives on cancer progression and can track the course of disease safely and with low cost. To be successful at this research requires a truly interdisciplinary effort, where the rapid advances in cancer biology are integrated with a precise understanding of how ultrasound interacts with tissues to view these processes. Consequently, our chapter begins with a review of modern theories of breast cancer formation and the interactions between ultrasonic energy and biological tissues.


Title Advances in the application of utlrasound in food analysis and processing.
Author McClements DJ.
Journal Trends Food Sci Technol
Volume
Year 1995
Abstract Ultrasonic techniques are finding increasing use in the food industry for both the analysis and modification of foods. Low-intensity ultrasound is a non-destructive technique that provides information about physicochemical properties, such as composition, structure, physical state and flow rate. High-intensity ultrasound is used to alter, either physically or chemically, the properties of foods, for example to generate emulsions, disrupt cells, promote chemical reactions, inhibit enzymes, tenderize meat and modify crystallization processes.


Title Age dependence of ultrasonically induced lung hemorrhage in mice.
Author Dalecki D, Child SZ, Raeman CH, Cox C, Penney DP, Carstensen EL.
Journal Ultrasound Med Biol
Volume
Year 1997
Abstract Thresholds for ultrasonically induced lung hemorrhage were determined in.neonatal mice (24-36 h old), juvenile mice (14 d old) and adult mice (8-10 weeks.old) to assess whether or not the threshold for lung hemorrhage is dependent.upon age. Ultrasonic exposures were at 1.15 MHz with a pulse length of 10.microseconds, pulse repetition frequency of 100 Hz and a total exposure duration.of 3 min. The threshold for lung hemorrhage occurred at a peak positive acoustic.pressure of approximately 1 MPa for mice in all three age groups. Although the.thresholds were similar for neonatal, juvenile and adult mice, the sizes of the.suprathreshold hemorrhages were significantly larger in adult mice than in.neonatal or juvenile mice. .


Title Age-dependent threshold and superthreshold behavior of ultrasound-induced lung hemorrhage in pigs.
Author O'Brien WD Jr, Simpson DG, Frizzell LA, Zachary JF.
Journal Proc Ultrason Symp IEEE
Volume
Year 2001
Abstract Age-dependent threshold and superthreshold behavior of ultrasound-induced lung hemorrhage was investigated with 116 4.9?1.6-day-old neonate crossbred pigs, 103 39?5-day-old crossbred pigs, and 104 58?5-day-old crossbred pigs. Exposure conditions were: 3.1 MHz, 10-s exposure duration, 1-kHz PRF, and 1.4-?s pulse duration. The in situ (at the pleural surface) peak rarefactional pressure ranged between 2.2 and 10.4 MPa with either 8 or 9 acoustic pressure groups for each of the three pig ages (12 pigs/exposure group) plus sham exposed pigs; there were no lesions in the shams. Pigs were exposed bilaterally with the order of exposure (left and right lung) and acoustic pressure both randomized. Logistic regression analysis was used to examine the dependence of the lesion incidence rates on in situ peak rarefactional pressure, left versus right lung, order of exposure (first versus second) and age in three categories. Likewise, lesion depth and root surface area were analyzed using Gaussian to bit regression analysis. A significant threshold effect on lesion occurrence was observed as a function of age; younger pigs were less susceptible to lung damage given equivalent in situ exposure. Oldest pigs had significantly lower thresholds (2.63?0.27 MPa) than middle-aged pigs (4.84?0.49 MPa). The oldest pigs also had lower thresholds than neonate pigs (3.62?0.44 MPa). Overall the oldest pigs were most sensitive to lung damage, and neonates were more susceptible than middle-aged pigs. Also, an unexpected result was observed. The ultrasound exposures were bilateral and the threshold results reported above were based on the lung that was first exposed. After the first lung was exposed, the pig was turned over and the other lung was exposed to the same acoustic pressure. There was a significant decrease (greater than the confidence limits) in threshold occurances: 3.62 to 2.67, 4.84 to 2.23 and 2.63 to 1.04 MPa, for neonates, middle-aged, and oldest pigs, respectively, in the second lung exposed. Thus, a subtle effect in lung physiology resulted in a major effect in the thresholds.


Title Age-related mechanical properties of human skin: An in vivo study.
Author Escoffier C, Rigal JD, Rochefort A, Vasselet R, Leveque JL, Agache PG.
Journal J Invest Dermatol
Volume
Year 1989
Abstract We have investigated in vivo how various viscoelastic parameters that describe the mechanical properties of the human skin may vary with age. Accordingly, we have used a mechanical device that records the torsional extensibility of the skin. When submitted to a low torque, the time-response curve of the skin affords the determination of the immediate extensibility (UE), the immediate recovery (UR), the viscoelastic part of the deformation (UV), the elastic recovery (UR/UE), and the creep relaxation time (tau). Because the skin thickness varies with age and primarily governs the mechanical properties, it was measured through an ultrasound technique at the same sites (forearm) where the torque was applied. The results show that the skin maintains its thickness and extensibility up to the seventh decade as opposed to its elasticity or recovery capacities, which decrease from an early age. The viscous part of the deformation is constant through life, whereas the creep relaxation time decreases linearily with age. Except for skin thickness, no differences in these parameters between men and women were detected. The significance of these results are discussed in terms of structure alterations. The determination of the elastic recovery (UR/UE) appears to be a parameter of choice for illustrating skin aging. ..


Title Agglomerated nuclei in ultrasonicated Vicia faba roots: A partial elucidation of their derivation.
Author Cataldo FL, Miller MW, Kaufman GE.
Journal Environ Exp Bot
Volume
Year 1976
Abstract An experiment was performed to determine whether ?Agglomerated Mitotic? cells, anomalies induced in Vicia faba root meristems by 2.0 MHz ultrasound, are in fact mitotic cells. Cells were synchronized at the G1/S border by hydroxyurea, ultrasonicated, the roots then transferred to fresh growth medium containing [3H]-thymidine, and examined at various times thereafter by autoradiography. Bridged Prophases, Bridged Metaphases, ?Agglomerated Mitotics?, and normal mitotics were scored for the presence or absence of radioactive label. Bridged Prophases, Bridged Metaphases, and normal mitotics appeared in the population at 22 hr following release from the G1/S block and were 3H-labelled, indicating transit through S-phase. ?Agglomerated Mitotics? appeared in the population much earlier (6 hr) and were unlabelled. Therefore, these ?Agglomerations? are no longer considered to be mitotic cells, and are instead thought to represent a morphological nuclear change induced in interphase cells by ultrasound.


Title Aggressive region growing for speckle reduction in ultrasound images.
Author Chen Y, Yin R, Flynn P, Broschat S.
Journal Pattern Rec Lett
Volume
Year 2003
Abstract Speckle appears in all conventional medical B-mode ultrasonic images and can be an undesirable property since it may mask small but diagnostically significant features. In this paper, an adaptive filtering algorithm is proposed for speckle reduction. It selects a filtering region size using an appropriately estimated homogeneity value for region growth. Homogeneous regions are processed with an arithmetic mean filter. Edge pixels are filtered using a nonlinear median filter. The performance of the proposed technique is compared to two other methods--the adaptive weighted median filter and the homogeneous region growing mean filter. Results of processed images show that the method proposed reduces speckle noise and preserves edge details effectively.


Title Airborne ultrasound: Measurement and possible adverse effects.
Author Herman BA, Powell D.
Journal Rep U S Dept HEW
Volume
Year 1981
Abstract A literature study was undertaken to investigate research efforts concerning possible adverse effects of airborne ultrasound on humans. Findings of this research, as well as proposed exposure-limiting criteria are presented. Measurement techniques for airborne ultrasound are reviewed and the results of output measurements of devices producing this acoustic radiation are discussed.


Title AIUM's position on reporting parameters of bioeffects experiments.
Author Edmonds PD.
Journal Ultrasound Med Biol
Volume
Year 1989
Abstract Abstract not available.


Title Albunex Does Not Increase the Sensitivity of the Lung to Pulsed Ultrasound.
Author Raeman CH, Dalecki D, Child SZ, Meltzer RS, Carstensen EL.
Journal Echocardiography
Volume
Year 1997
Abstract If cavitation in the vasculature of the lung is the physical mechanism responsible for lung hemorrhage, then addition of cavitation nuclei to the blood should enhance the bioeffect. To test the cavitation hypothesis, the extent of lung hemorrhage in mice injected with the echocontrast agent, Albunex(R), was compared to lung hemorrhage in animals injected with saline. Animals were exposed for 5 minutes to 1.1-MHz pulsed ultrasound (10 µs pulse length, 100-Hz pulse repetition frequency) at a peak positive pressure at the surface of the animal of 2 MPa. This exposure is approximately twice the threshold pressure amplitude for lung hemorrhage. Lesion areas did not differ significantly in the two groups of animals and were approximately equal to the lesion area in uninjected mice from an earlier study where acoustic exposures were the same. Neither this study nor a related study of hemolysis in vivo suggests that use of Albunex in echocardiographic procedures increases the risk of bioeffects.


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