Ultrasound- 2D Daniel Azan, Annie Nunez, Sheidyn Ng
What is an Ultrasound? Ultrasound imaging involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body http://www.radiologyinfo.org/en/info.cfm?pg=genus http://en.wikipedia.org/wiki/File:Ultrasound_range_diagram.png
Advantages of Ultrasound Painless and harmless Non-invasive Non ionizing radiation Show Soft Tissue missed by X-Ray Relative inexpensive and immediate image display Portable http://www.radiologyinfo.org/en/info.cfm?pg=genus
Disadvantages of Ultrasound Can’t Penetrate bone and gas Resolution limitations Cannot show motion Technique-dependent http://www.radiologyinfo.org/en/info.cfm?pg=genus
Ulrasonography Obstetric sonogram of a fetus at 16 weeks.
Delivering chemotherapy to brain cancer cells and various drugs to other tissues is called Acoustic Targeted Drug Delivery(ATDD). These procedures generally use high frequency ultrasound(1-10Mhz) and rage of intensities(0-20 watts/cm2). The acoustic energy is focused on the tissue of interest to agitate its matrix and make it more permeable to therapeutic drugs. Drug Delivery
Physical Therapy Frequency range for physical therapy applications is 0.8 to 3.0 MHz Thermal effects heat Non thermal effects vibration Stimulates cell membranes and enhance the cell-repair effects of the inflammatory response http://www.automailer.com/tws/ultrasound.html
Non-Medical Applications: SONAR
During World War I, with the invention of submarines came the need to locate them. Research of underwater sound location was a primary focus for the British. Both the U.S. and Britain were researching what would be Sonar, and it was kept secret throughout the war. By 1922, units were being produced and by 1923, they were being equipped to naval vessels.
Radar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. Before the Second World War developments by the British, the Germans, the French, the Soviets and the Americans led to the modern version of radar. American Dr. Robert M. Page tested the first monopulse radar and the Soviet military engineer P.K.Oschepkov, in collaboration with Leningrad Electrophysical Institute, produced an experimental apparatus capable of detecting an aircraft within 3 km of a receiver. However, it was the British who were the first to fully exploit it as a defense against aircraft attack.
Ultrasound Medical Timeline Karl Theo Dussik, begun experiments in the late 1930s, was generally regarded as the first physician to have employed ultrasound in medical diagnosis. H Gohr and Th. Wedekind, during the 1940s presented in their paper "Der Ultraschall in der Medizin" the possibility of ultrasonic diagnosis basing on echo-reflection methods similar to that used in metal flaw detection. James Griffith and Walter Henry produced a mechanical oscillating real-time scanning apparatus in 1973 which was capable of producing clear 30 degree sectoral real-time images of good resolution. http://www.ob-ultrasound.net/history1.html
Martin H Wilcox at the Advanced Diagnostic Research Corporation designed and produced one of the earliest commercially available models of a linear-array real-time scanner in 1973. The array contained 64 crystals in a row, fabricated with the best material available and in the best acoustic configurations using 'stepping' crystals techniques. Albert Macovski in 1974 developed circular array where the elements generate dynamically focused beams that could also be swept through space by adjusting the delays to the array. This was one of the more advanced designs in dynamic focusing techniques. In 1976 Toshiba® produced their first commercial real-time linear array counterpart in the same year, the SSL-53H, aimed at abdominal applications. http://www.ob-ultrasound.net/toshiba_realtime.html http://www.ob-ultrasound.net/history2.html
Ultrasound guidance was started to be employed in procedures such as amniocentesis (Jens Bang and Allen Northeved1972, Copenhagen), fetoscopy (John Hobbins and Maurice Mahoney, 1974) and transabdominal chorionic villus sampling (Steen Smidt-Jensen and N Hahnemann, 1984, Copenhagen).
The Kossoff group in Australia had also made significant progress in the annular phased array transducer designs as early as 1973 and the technology was incoporated into their water-bath scanner, the UI Octoson.
In the early 1980sresearch concluded that mechanical sector scanners which employed relatively large area transducers produced better and less noisy images than electronic linear-array scanners.
Toshiba® introduced a similar array in 1985, in their new scanner model SAL-77A. Interestingly, the design actually replaced an earlier model (by only about 9 months) the SAL-90A which boasted a new "trapezoid" linear array in which the face of the transducer was flat but a trapezoid-shaped image was produced from the 128 transducer elements using phased electronics.. By about 1987, convex arrays are standard on every new scanner, whether or not it is configured for use in Obstetrics and Gynecology.
Dutch manufacturer Philips® followed on with one of the earliest mechanical vaginal scanners in the second half of 1986. The probe was in the shape of a microphone with a roundish elongated head housing a 5MHz 13mm wobbler transducer. It could be retro-fitted onto their real-time scanner SDR 1550 which first debuted in 1985
The assessment of ovarian follicular development had before that been based on static and real-time abdominal ultrasound, first popularised by B-Joachim Hackelöer and his group in Germany since 1977.
ChihiroKasai, KorokuNamekawa, Ryozo Omoto and co-workers in Tokyo led the widespread realization that real-time color flow imaging could be a practical possibility. The group had already reported on the technical details and clinical (cardiac) applications in the Japanese language in 1983.
Quantum Medical Systems®, Issaquah, Washington, started introducing the concept of real-time color doppler imaging at the AIUM meeting in the fall of 1983. The first color images were shown at the RSNA meeting in December 1984
Quantum® marketed their first machine, the QAD-1 in 1986 which produced some very impressive real-time color flow images of the carotid and other arteries basing on the newer array technology. They called it "AngioDynography" although the term had not subsequently become popular.
Color flow imaging made it's real impact in the United States in 1987 and in Europe in the following year. ATL® after some re-organization, marketed its first color doppler machine, the UltraMark 9 in 1988
In the early 1990's ultrasound found its way into the assessment of Gynecological and early pregnancy abnormalities.
rmonic imaging would not have been possible until the late 1990s as there must be excellent beam linearity on transmission and super sensitivity and dynamic range on receive to display the harmonic energy without an unacceptable amount of noise, as the harmonic signals are always much less in amplitude than the original fundamental signal. There must also be a very selective and fast digital filter within the receiver, to exclude the large percentage of the fundamental signal. Harmonic imaging is particularly useful in obese patients. The 1990s showed advancements in Ultrasound technology via The entire signal processing chain becomes digital Extensive use of refined broad-band wide aperture transducers The phase data in returning ultrasound echoes The advent of tissue harmonic imaging http://www.ob-ultrasound.net/history3.html
Over 80 million Ultrasounds examinations are conducted every year in the US.
Women who having multiple babies typically get an Ultrasound every 4 weeks in the second and third trimester.
If there are any difficultly during pregnancy, they may have 2-3 ultrasounds per week during their third trimester.
In 2002, Massachusetts General Hospital reported that they conducted 150 to 200 ultrasound exams per day.
Therefore, using that statistic about 50,000 to 70,000 ultrasound exams are performed at Massachusetts General Hospital alone.
Breakdown of Examinations at Massachusetts General Hospital in 2002 http://www.gehealthcare.com/usen/ultrasound/docs/ult_vip_0264.pdf http://www.see3d.ca/3D_Ultrasound_Faq.php
Summary 2-D Ultrasounds are still a reliable and effective imaging technology used in various parts of the medical field such as OB, gastroenterology and cardiology. In addition, the cost for 2-D ultrasounds are cheaper in compared to 3D and 4D ultrasound examinations. http://www.imagesfromthewomb.com/4d-ultrasound.html