Although intermittent imaging (II) dramatically increases the myocardial contrast produced from an intravenous injection of perfluorocarbon containing microbubbles (PCMB), it is still unknown how different diagnostic ultrasound (DU) transducer frequencies (TF), acoustic outputs (AO), and frame rates (FR) affect the size distribution and concentration (cone) of PCMB over the range of physiologic How rates (FR) and body temperatures (BT). The purpose of this project was to determine how these DU variables affect the size and cone of PCMB MB at physiologic FR in saline or blood at 37 Celsius (C). The size and cone of PCMB were measured following a 0.1 milliliter injection of PCMB proximal to a scanning chamber containing blood or saline flowing at 20,50, or 100 ml/min. Inosonation TF ranged from 2.0 to 7.5 megahertz (MHZ), and AO of 0.1, 0.4, and 1.1 megapascals(MPa). 1 Hz FR was compared to 30 Hz FR and DO DU. Results. At all FR, PCMB size increased when exposed to BT. At 2.0 MHZ, PCMB cone was reduced when using a 30 Hz FR and 1.1 MPa. This destruction did not occur when a lower AO, a higher TF, a 100 cc/min flow rate, or 1 Hz FR. The 1 Hz FR at 2.0 MHZ and 1.1 MPa selectively destroyed smaller MB: (Figure Presented) We conclude mat the greatest destruction of PCMB by DU occurs with low TF, 30 Hz ER and high AO. One Hertz FR (or II) reduces this destruction, but also selectively destroys the smaller MB. II produces greater MC than conventional FR by either preventing destruction of larger MB or by producing a cavitational emission from smaller PCMB.
|Original language||English (US)|
|Number of pages||1|
|Journal||Journal of the American Society of Echocardiography|
|State||Published - 1997|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine