Harmonic imaging of porcine intraovarian arteries using sonographic contrast medium: initial findings

The purpose of this study was to visualize, using harmonic gray-scale imaging, blood flow in porcine intraovarian arteries after intravenous injections of a bubble-based sonographic contrast medium. Five female pigs underwent laparotomy. Surgically isolated ovaries were scanned intraperitoneally by an ultrasound system reconfigured with software changes to accomplish harmonic imaging. The transmission and receiving frequencies were set at 3.75 and 7.5 MHz, respectively. After injection of the sonographic contrast medium (Aerosomes) into a peripheral vein, the ovaries were imaged in the harmonic mode. Ten minutes later, another contrast injection was administered and conventional gray-scale imaging of the ovary performed. In all five pigs, intraovarian arteries were clearly identified upon harmonic imaging as brightly echogenic moving columns. The arterial blood pool appeared brighter during systole than diastole. Upon ultrasound contrast-assisted conventional gray-scale imaging, intraovarian arteries were not visualized in four pigs and poorly visualized in one. We conclude that contrast-assisted harmonic imaging can adequately visualize blood flow in intraovarian arteries of surgically exposed porcine ovaries. Clinically, harmonic imaging may facilitate early detection of tumor-induced angiogenesis in the human ovary.