Properties of contrast agents insonified at frequencies above 10 MHz

The authors compare the properties of contrast agents following insonation in the 3-7 MHz range with the properties observed at higher frequencies, in order to differentiate the properties associated with insonation near resonance. In addition, to map small blood vessels located in deeper tissues, such as those within the retina and within lymph nodes, contrast-enhanced imaging at high frequencies may be desirable. Increasing the echo intensity with a contrast agent may allow the use of a higher frequency transducer, and thus improve the spatial resolution of the vascular map. With these goals in mind, the authors explore the properties of ultrasonic echoes from contrast agents at 38 MHz and compare these properties to those at lower frequencies.