Contrast-enhanced ultrasound

In contrast-enhanced ultrasound ultrasound contrast agents are used in the ultrasound or echocardiography. These contrast agents are gas-filled microbubbles ( "micro bubbles" ), which are given intravenously in most applications and are either respirable or non- respirable. Contrast agents are very echogenic.

Applications

Abdomen

• Detection and characterization of liver tumors: Here one makes a special feature of the liver advantage. Blood supply of the liver takes place in contrast to all the other elements ( except pituitary ) adjacent arteries and veins through the portal vein, which supplies nutrient-rich blood from the gut. Sprayed contrast agent into a vein in the arm, so this is first pass via the arteries to the liver, then the contrast medium is flowing down into the hepatic veins represents the influx of the contrast medium in the portal vein takes the longest (20-30 s ), since the blood circulates only in the intestine and then passes to the liver. Custom liver tissue is therefore included in this so-called late phase of contrast agent. Of course liver metastases of other tumors do not contain a portal system and thus appear contrast- free (dark). Some tumors arise in contrast enhanced ultrasound so typical is that dispenses with them on a liver biopsy now. Focal nodular hyperplasia ( FNH ): If supplied by a vascular system with Radspeichenmuster.
• Hemangioma: From the time course of the contrast agent flooding from outside to inside ( " iris " phenomenon ) is closed on a hemangioma.

Cardiology

For the detection of cardiac shunts such as the persistent foramen ovale with the investigation shall not respirable contrast agents in a transesophageal echocardiography as the gold standard. Respirable contrast agents are recommended by the European Association of Echocardiography in their expert consensus at suboptimal stress echocardiography studies to improve the Endokardabgrenzung and therefore more reliable to assess the wall motion. Some ultrasound systems can simultaneously represent the myocardial perfusion, which is reduced in coronary heart disease under load, but also in acute myocardial infarction.

Gynecology

In the area of ​​diagnosis of fertility problems the hystero - contrast - Salpingography place to check the patency of the fallopian tube application.

Pediatrics

Main article Miktionsurosonografie

To backflow ( reflux ) of urine from the bladder to exclude in the kidney: This study, called Miktionsurosonografie ( MUS ), can replace the previously performed X-ray examination with contrast medium ( Miktionscystourogramm MCU). In this manner, a reflux test without radiation exposure is possible. Because the delicate gonads regularly lie in the x-ray examination of the useful beam, this is a great advantage.

To the boy's urethra with display (because boys can PUV ( posterior urethral valves ), but not girls ), the initial examination usually takes place in the course of investigations boy MCU as a classic, but then as MUS.

Microbubbles

On the market there are respirable and non- respirable contrast agents consist of microbubbles ( "micro bubbles" ) and differ mainly in their cases and their gas content. They are about 1-4 microns in size.

In the ultrasonic field microbubbles begin to oscillate. At higher sound pressure levels and non-linear vibrations of high amplitude, which can be easily separated from signals from the tissue and thus make it possible to monitor the blood supply of tissues originate.

• Microbubbles with increasing sound pressure amplitude of the ultrasound

Ultrasonic backscattered nonlinear

The microbubble is destroyed