Ultrasonography is one of the modern methods of diagnosis in medicine. The system relies on ultrasounds, which are sound waves that are too high for the ears to detect. It is a painless, harmless and non-invasive method that does not rely on radiation. It can be used to detect problems with the internal organs of the human body. The use of ultrasonography makes it easy for diagnosis in gynecology, cardiology, urology and endocrinology. Because of its non-invasive nature, ultrasonography is used as the first line of diagnosis before other invasive methods are used.
How It Works
The system relies on a probe that contains acoustic transducers. These transducers send pulses into the body. When the sound waves sent by the transducers encounter an obstacle, that is a material with different acoustic impedance, a reflection is sent back to the probe in the form of an echo. The time the echo takes to travel back to the probe is calculated and used to calculate the depth of the tissue that is encountered. If the acoustic impedance is high, the echo is larger.
Doppler and Ultrasonography
Doppler measurements help a lot in making ultrasound images better. The calculation of the Doppler's effect makes it possible to detect whether blood is flowing to or from the organ being viewed or not. The Doppler measurements are very useful for cardiovascular studies. This information can be displayed in graphics using spectral Doppler. These sounds can be heard by using stereo speakers.
Types of Images Produced
Ultrasonography is capable of producing various kinds of images. To produce a 2D-image, the probe is swiveled mechanically or made to phase an array of transducers. The data is collected and analyzed on a computer which then constructs the images. By using specialized probes, 3D-images can be produced using the same procedure. The regular color of ultrasound images is black and white, but it is now possible to produce some kinds of color images by analyzing the amount of energy of each echo and assigning a color to the differences in acoustic impedance.
Strengths of Ultrasonography
The use of ultrasonography makes it possible to make images of soft tissues and to differentiate clearly between solids and fluid filled spaces. It makes diagnosis easy as it gives instant images so that the most useful can be selected by the operator. Ultrasonography allows for the structure of the organs to be detected as well as to determine how the organ is functioning, to some extent. There are no known side effects of this method, and the process does not cause any discomfort to the patient. The relatively small size of the scanners makes it possible to carry it anywhere.
Weaknesses of Ultrasonography
The basic ultrasound devices cannot penetrate bones; but ongoing programs are geared towards making it possible for bone imaging through ultrasound technology. When a gas exists between the device and the target organ, there is a lot of difficulty using ultrasound. This makes scanning of certain organs like the pancreas almost impossible. Ultrasound cannot penetrate deep into the body; this makes diagnosing organs that are deep in the body very difficult. The method depends highly on the operator who should be highly skilled and experienced in order to produce the quality images needed for the right diagnosis.
Tags: acoustic impedance, makes possible, back probe, cannot penetrate, Doppler measurements
