The Vscan is a palm-size ultrasound scanner, which has both anatomical imaging and color Doppler capability. The device is currently in clinical use and costs considerably less than a full-sized ultrasound scanner. Its small size and low cost, as well as range of applications, allow it to be used in ambulances, emergency rooms, field hospitals, or other remote locations. It is currently being used in more than 60 countries around the world.
Vscan image on right courtesy of Kai Thomenius, Ph. Histotripsy technique for dissolving blood clots. Researchers at the University of Michigan are investigating the clot-dissolving capabilities of a high intensity ultrasound technique, called histotripsy, for the non-invasive treatment of deep-vein thrombosis DVT. This technique uses short, high-intensity pulses of ultrasound to cause clot breakdown. The researchers have successfully demonstrated the effectiveness of this technique in pigs and its possible use in humans.
They are currently working on new methods to avoid inadvertent vessel damage during clot treatment, and to provide real-time imaging feedback to monitor the treatment. This research could have a significant impact, since current conventional treatments for DVT involve drug therapy and sometimes invasive removal of the clots, which requires a several-day hospital stay, and may result in complications after treatment.
In contrast, the non-invasive histotripsy technique is 50 times faster than the current technique, does not require drugs or external agents, and if successful, could be used as an outpatient procedure.
How does it work? What is ultrasound used for? Are there risks? What is medical ultrasound? Diagnostic ultrasound is a non-invasive diagnostic technique used to image inside the body. Ultrasound probes, called transducers, produce sound waves that have frequencies above the threshold of human hearing above 20KHz , but most transducers in current use operate at much higher frequencies in the megahertz MHz range.
Most diagnostic ultrasound probes are placed on the skin. However, to optimize image quality, probes may be placed inside the body via the gastrointestinal tract, vagina, or blood vessels. In addition, ultrasound is sometimes used during surgery by placing a sterile probe into the area being operated on.
Source: Terese Winslow Ultrasound waves are produced by a transducer, which can both emit ultrasound waves, as well as detect the ultrasound echoes reflected back. An ultrasound transducer.
The ultrasound probe transducer is placed over the carotid artery top. A color ultrasound image bottom, left shows blood flow the red color in the image in the carotid artery.
Waveform image bottom right shows the sound of flowing blood in the carotid artery. Click here to watch video Ultrasound color Doppler shows a clot blocking blood flow in a pig.
Source: Zhen Xu, Ph. In , SY Sokolov , a Soviet physicist, first proposed the idea of ultrasound to find flaws deep in metal structures. Indeed the successful use of ultrasound in industry predated its introduction into clinical medicine. These early sonographic methods in industrial manufacture used "through transmission".
A receiver on the opposing side of the material to the ultrasound transmitter detected the sound waves as they passed through the material under testing, creating 'shadows' that could be interpreted.
During the s, efforts to use reflective techniques were made, which of course required that the receiver was on the same side of the material as the transmitter. Donald Sproule , a researcher working in England in created a system in which the receiver was a separate device collecting the waves that had bounced off the material. In , Floyd Firestone , working in the US, received a patent for the Reflectoscope, the first system in which the same transducer both generated the ultrasound waves, and also detected the reflected waves, in the time between transmitted wave pulses.
In , Karl Dussik , an Austrian physician, and his brother Friederick , a physicist, introduced hyperphonography, a technique which used ultrasound to visualize the cerebral ventricles. Unfortunately, W Guttner, working in Germany showed that the apparent 'pictures' of ventricles were nothing of the kind, but instead represented densities of different parts of the overlying skull!
George Ludwig , working at the Naval Military Research Institute, in the United States, in , carried out research into gallstones embedded in soft tissues, using a through transmission technique. His pioneering investigations into the interactions between ultrasonic waves and animal tissues, helped lay the foundations for the later successful use of ultrasound in medical practice.
Ian Donald introduced the ultrasound in diagnostic and medicine in , when he used the one-dimensional A-mode amplitude mode to measure the parietal diameter of the fetal head. Two years later, Donald and Brown presented the ultrasound image of a female genital tumor.
A decade later the Doppler effect served as the basis for the construction of the device that enabled the visualization of blood circulation, color flow Doppler ultrasound.
Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Updating… Please wait. Unable to process the form. Check for errors and try again. Thank you for updating your details. Log In. Ultrasound was first used for clinical purposes in in Glasgow. Obstetrician Ian Donald and engineer Tom Brown developed the first prototype systems based on an instrument used to detect industrial flaws in ships.
They perfected its clinical use, and by the end of the s, ultrasound was routinely used in Glasgow hospitals, Nicolson said. By the end of the 20th century, ultrasound imaging had become routine in maternity clinics throughout the developed world.
The technology has undergone extensive development over the past 20 years, Nicolson told LiveScience, but "has probably reached more or less the pinnacle of its acuity.
Ultrasound imaging involves bouncing "ultrasonic" sound waves — above the audible range of human hearing — at body structures or tissues, and detecting the echoes that bounce back. Obstetric ultrasonography is used to image a human fetus inside its mother's womb. It's used to confirm a pregnancy, to identify the sex and number of fetuses and to detect fetal abnormalities such as microcephaly an abnormally small head , absence of kidneys, and spinal problems.
During a scan, ultrasound waves are aimed at a pregnant women's abdomen. Based on the angle of the beam, and the time it takes for echoes to return, an image of body structures inside the fetus can be generated. Early in the use of fetal ultrasound, clinicians could only detect the baby's head, Nicolson said. One of the main advantages of ultrasound is that it's noninvasive.
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