In this chapter the physics of medical ultrasound will be discussed at an introductory level for users of the technology. Several texts exist which readers can consult to deepen their understanding. Discussed later in this chapter are parameters related to ultrasound in tissue such as speed of ultrasound, attenuation and acoustic impedance. Values of these parameters for commonly encountered ti...

Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a noninvasive image-guided technique used to thermally ablate solid tumors. During treatment, ultrasound reflections from distal media interfaces can shift prescribed treatment locations. The purpose of this study was to investigate the effect of normal incidence reflections from air, acrylic (modeling bone), and rubber on...

Modern ultrasound imaging for diagnostic purposes has a wide range of applications. It is used in obstetrics to monitor the progress of pregnancy, in oncology to visualize tumours and their response to treatment, and, in cardiology, contrast-enhanced studies are used to investigate heart function and physiology. An increasing use of diagnostic ultrasound is to provide the first photograph for b...

BACKGROUND Transrectal ultrasound-guided prostate needle biopsies are performed to diagnose prostate cancer. This study prospectively evaluated the safety, morbidity and complication rates with two different ultrasound probes. PATIENTS AND METHODS Three huntred and thirty-two patients were biopsied using a biplane 7.5 MHz probe (GE Medical Systems Kretz Ultrasound, Zipf, Austria) and 101 pati...

Ultrasound-assisted drug delivery is an emerging technique that has the advantage of being non-invasive, efficiently and specifically targeted and controllable. While systemic drugs often show detrimental side effects, their ultrasound-triggered local release at the selected tissue may improve safety and specifity of therapy. An increasing amount of animal and preclinical studies demonstrates h...

Modern ultrasound imaging for diagnostic purposes has a wide range of applications. It is used in obstetrics to monitor the progress of pregnancy, in oncology to visualize tumours and their response to treatment, and, in cardiology, contrast-enhanced studies are used to investigate heart function and physiology. An increasing use of diagnostic ultrasound is to provide the first photograph for b...

The American Conference of Governmental Industrial Hygienists (ACGIH) increased the threshold level Values (TLVs) for airborne ultrasound and these levels were adopted by Occupational Safety and Health Administration (OSHA) in 2003. The European community, Australia and Canada have retained the more stringent levels that stemmed from reports of “ultrasonic sickness” in the 1960s. Ultrasound can...

The therapeutic use of ultrasound contrast agents (UCAs) is an emerging methodology with high potential for enhanced directed therapeutic gene, bioactive gas, drug, and stem cell delivery. Ultrasound-targeted microbubble destruction has already demonstrated feasibility for plasmid DNA delivery. Similarly, therapeutic ultrasound for thrombolysis treatment has been taken into the clinical setting...

Investigations into the safety of ultrasonography in pregnancy have focused on the potential harm of ultrasound itself. However, no data have been published regarding the electromagnetic fields that ultrasound devices might produce. This study is the first to measure extremely low-frequency magnetic field (ELF-MF) exposure of clinicians and pregnant women during prenatal ultrasound examinations...

BACKGROUND The eye's unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. METHODS An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sh...