2002 年 15 巻 1 号 p. 1-4
Recently, the technique of harmonic contrast imaging has been developed which exploits the nonlinear properties of ultrasound contrast agents by processing the second harmonic echo signal of the transmitted ultrasound pulse. The contrast agent employed is Levovist (Schering), which was released in Japan in 1999. The advantage of harmonic imaging is its selective imaging of differences between tissue and blood perfusion areas.
The purpose of the present study was to investigate a method of detecting human brain perfusion by ultrasound with second harmonic signals and contrast agents in eight patients with brain tumors. We used pulse inversion harmonic imaging, which is the latest technique for visualizing ultrasound contrast agents, thereby allowing us to image brain perfusion, and well enhanced perfusion images were obtained in all cases.We performed analysis resulting in wash-in wash-out curves, and concluded that this method could be used for diagnosis of brain hemodynamics.