Recent advances in biomedical ultrasonic imaging techniques

Abstract

Nowadays in the UK, more than one quarter of all clinical imaging procedures use ultrasound and the number of ultrasonic scans that are performed each year exceeds all of those done by X-ray computed tomography, magnetic resonance imaging and radionuclide scanning combined [1]. Doubtless, the situation is similar in the rest of the world, but with ultrasound being even more used in lessdeveloped countries, because of its relatively low cost. Diagnostic ultrasound has come into its ascendency over the last 60 years, mutating from a laboratory curiosity being developed and promoted by very few innovative engineers and visionary clinicians (for instance, in the USA [2], in Japan (see [3]), in Sweden [4] and in the UK [5]) into an indispensible tool in modern routine clinical practice.Each of the wide range of different imaging modalities has its own individual characteristics. Usually in practice, the choice of the optimal modality is fairly obvious, because it depends on the clinical problem being investigated. Thus, for example, an X-ray is appropriate if a fracture is suspected, because X-rays are good at imaging bones. Likewise, for the management of cancer, positron emission tomography-a type of radionuclide scanning-can be invaluable because of its ability to visualize malignant tissue. The relative advantage of any particular modality lies essentially in the mechanism of the contrast in the images which it produces. In this respect, ultrasonic imaging is rather versatile. Primarily, the image contrast depends on differences in densities and speeds of sound, because these properties determine the scattering and reflectivity of tissue. In addition, flow, motion, strain and elasticity can be estimated ultrasonically and used to produce parametric images, for example, by colour maps superimposed on images of scattering and reflectivity. Moreover, ultrasonic imaging is fast and apparently safe, as well as being well liked by patients. Thus, the technology is particularly valuable in clinical practice in obstetrics and gynaecology, internal medicine, genitourinary studies, cardiology, vascular studies, dermatology and breast disease, but it is not of much use in the investigation of gas-containing or bony structures.Ultrasonic imaging is a mature medical technology, the evolution of which has been the result of many years of biomedical engineering and clinical research. Moreover, the level of contemporary research activity is great and it covers a vast range of emerging opportunities. Very many ultrasound papers appear in medical journals devoted to the various clinical specialties and these generally report on the expansion of the diagnostic horizons, which results from novel applications and observations with existingalbeit often new-technologies. In organizing this Theme Issue of Interface Focus, however, we sought to compile papers that would be representative of advances in the technologies themselves, sometimes even before their clinical potentials have been explored. Of course, our intention certainly was ...

Bubbles with shock waves and ultrasound: a review

“…UCA [6,7]. A clear distinction should be made, however, between endogenous cavitation nuclei, which we study in the rest of this article, and artificially introduced nuclei, such as the UCA.…”

Nonlinear ultrasound imaging of nanoscale acoustic biomolecules

“…Ultrasound is a widely used biomedical imaging modality 1 that enables the assessment of organ anatomy and function with high spatial and temporal resolution (typically <500 lm and 10 ms). 2 However, the role of ultrasound in molecular and cellular imaging remains limited due to a lack of contrast agents and reporter genes able to target specific tissues or visualize cellular processes such as gene expression.…”

Classification of atherosclerotic and non-atherosclerotic individuals using multiclass support vector machine

“…The Entry dataset consists of 1417 patient records with 64 attributes having either codes or results of size measurements of different variables or results of transformations of the rest of the attributes during the first-level In this work a new dataset is formed by combining the entry, control and death datasets. The entry dataset is divided into three groups namely, (i) Normal Group (NG) (ii) Risk Group (RG) and (iii) Pathologic Group (PG), based on the studied group of patients (KONSKUP) in (1, 2), (5), (3,4), and (HODN11), Operation on lower limb arteries (HODN23). Based on the above factors and other serious disease, making the individuals ten-year-long observation impossible (e.g.…”

“…The imaging of atherosclerosis can be done in two modes, 1) invasive and 2) non invasive. The invasive methods, X-ray angiography is one of the standard techniques of atherosclerosis imaging even though it has certain limitations in providing information on plaque composition [3]. The other invasive procedures such as intravascular ultrasound [4] and angioscopy [5] help in empathizing plaque size to a limited extent in its composition.…”