مشروع البحث: Ultrasoun imaging theoritical and evalution study
تحميل...
المساهمين
الممولين
رقم التعريف
5935
الباحث
جمعة محمد صالح
الوصف
An ultrasound image is formed by scanning an ultrasound beam over a body section. In each scan line or beam position a pulse is transmitted into the body. If there are structures within the beam that produce reflections, the echo pulses return to the transducer where they are converted into an electrical pulse and processed to form the image. The resulting image is essentially a map showing the echo producing sites. Two factors are used to determine the location of the echo producing structures.
The depth or distance from the transducer to a site is measured by the time interval between the transmission of the pulse and the reception of the returning echo. The horizontal or lateral location of an echo site is determined by knowing the location of the beam that produced a specific echo[1-2]. Ultrasound includes all sound waves above the frequency of human hearing about 20 thousand Hertz, or cycles per second. Medical ultrasound generally uses frequencies between 1 of 10 million Hertz (1–10MHz). Higher frequency ultrasound waves produce more detailed images, but are also more readily absorbed and so cannot penetrate as deeply into the body.
الكلمات الدالة
imaging theoritical and evalution study