Yoshifumi Saijo

    The world's first ultrasound cardiac tomogram was developed at Tohoku University through a medical-engineering collaboration. Since then, we have been conducting internationally original ultrasound research. Here multiscale blood flow imaging by ultrasound and photoacoustic imaging methods are introduced. Among the imaging modalities currently used in clinical practice, the greatest advantage of ultrasound measurement is its high temporal resolution. In particular, real-time blood flow measurement can be performed by taking full advantage of its high temporal resolution. Here, the principle of Doppler blood flow measurement and the latest technology for correcting aliasing, which is a drawback of Doppler measurement, will be presented along with clinical images of cardiovascular blood flow. The principles and validation of “echo-dynamography” and vector projectile imaging, two new imaging methods for two-dimensional blood flow vectors, are also described. For imaging of peripheral blood flow, high-resolution imaging using high-frequency ultrasound, detection of micro vessels using singular value resolution, and recently developed photoacoustic imaging that can visualize microvasculature and even a single red blood cell will be presented.