Ultrasound (Sonography)

Ultrasound is the most commonly used imaging techniques in medicine. It is used for diagnostic purposes, as a screening examination to the course of therapy to control or they can judge. When ultrasonic sound waves are used, which are far above the hearing threshold and by the human ear can not be perceived. Ultrasound is acoustic energy, which is sent into the body, reflected there, the transmission location again received and is presented as optical image. The implementation of sound into images called sonography, which stands for drawing or writing by sound. This process is used for imaging of internal body structures and shows his great strength, especially in the soft tissue diagnosis. Ultrasound makes a gentle and painless examination of the organs without radiation exposure to humans.

The development of ultrasound devices began in the 1950s, with devices for studies of the skull and the heart. This was followed by ultrasound examinations of the organs in the abdominal area, the thyroid gland as well as obstetrical literary stakes. Today, a large diagnostic sonography width. Meanwhile, combination devices are used in which multiple scanning methods can be applied.
Preparations for a ultrasonic examination

For a sonographic examination, it is hardly necessary preparations. Gallbladder or pancreas are examined, the examiner to appear sober, can be excluded so that air (gas) is derived in the abdominal cavity, the sound waves. Be filled for an ultrasound in the pelvis, the bladder, so that it can displace the small bowel from the pelvis. Before starting the scanning process is applied to the skin surface of the region to be examined one electrode cream, which prevents air between the transducer and the skin, the sound waves is derived.
Process and therapeutic procedures

The survey instrument consists of a computer monitor on which the image is evaluated, and a transducer, which also serves as a transmitter and receiver. The transducer is located directly on the skin and sends sound waves into the body. The waves are reflected by tissue to varying degrees and as an echo from the transducer resumed. From the difference between the transmitted and received waves create an image of the computer. Tissue reflects the brighter the better it will be mapped. The reflection strength, however, depends on the density of the tissue examined. Is particularly visible bones. This does not sound at all through, but throws it back completely. The picture is bone, such as on a radiograph, white. Water-and blood-rich organs have different densities and sound are evaluated the various shades of gray. Fluid-filled cavities, such as cysts, can be delimited from the surrounding tissue very well. For this let the sound through fully and are shown in black in the evaluation. Principle are difficult to investigate gas-containing organs or hidden by bone.

For sonography is a variety of investigative methods. Depending on the problem and regions studied different devices and settings are used.

A-scan ultrasonography (A-Mode): This is hardly used today. The acquired dimensional sound reflections are displayed in a diagram.

B-mode ultrasound (B-mode): The echo signals are obtained as two-dimensional slice images visualized in grayscale. The B-mode is currently the most widely used variant of ultrasound imaging in medicine.

M-mode: with these movements (such as heart valves rhythm) map of moving organs. These movements are played in one-dimensional diagrams.

Echocardiography / Doppler ultrasound: This technique is used for flow measurements in the heart and blood vessels. The reflected echoes of the moving red blood cells is done electronically and audibly recorded as a curve.

Duplex ultrasound: This test is shown the blood flow acoustically and visually. This is supported by a color coding method. The blood flow to the transducer back and away from him, is marked in different colors. Changes in flow rates can thus be diagnosed.

3D ultrasound: This is a sectional illustration taken from two-dimensional image planes. The computer evaluates the two-dimensional images and can thus calculate a third image plane. In these processes occur photo-realistic images.
Applications of ultrasound examination

In almost every field of medicine, sonography is used as a method of examination. It is used for evaluation and assessment of medical records for clinical monitoring of therapy, as well as a screening tool. The applications listed here can only give an example, which has great benefits for medical sonography.

Pregnancy Diagnosis: Because of their gentle method for the organism, the ultrasound examination taken in this area an important role. It is used as pregnancy tests, position, size, age and sex determination of fetuses, detection of multiple pregnancies and malformations. A popular method of pregnancy diagnosis established slowly 3D sonography. The three-dimensional images are used for monitoring high-risk pregnancies and structures for the representation of childhood.

Soft tissue diagnostics: tests of the thyroid, female breast, testis, and the muscles and joints
Basic research: search for cancer and metastatic foci

Investigations in the abdomen: liver, gallbladder, pancreas, spleen, and draining harnproduzierende organs, male and female sex organs
Basic research: search for cancer and metastatic foci, suspected kidney stones and gallstones, inflammation, cancer screening

Vascular Diagnosis: stenosis or occlusions of the arteries and veins in the abdomen, leg and neck
Basic investigation: suspected venous thrombosis, arteriosclerosis, varicose veins

Cardiac diagnosis: to verify the functionality or pathological changes in heart muscle
Basic investigation: suspected pericarditis, the heart valves Funktionsstörrungen

Image guided biopsy is the removal of tissue used ultrasonography to visualize
Basic research: to distinguish between benign and malignant tissue
Complications and risks of ultrasound examination

Sonography is a risk-free examination. After-or side effects to the person examined, the fetus or the user are not known.
Alternatives to the ultrasound

As the ultrasound examination process is a cost effective and repeatable method as often and is therefore often used for initial diagnosis before a magnetic resonance imaging or computed tomography. Nevertheless, it should always be in the context of history and other imaging findings are considered.