PROBLEM TO BE SOLVED: To provide an ultrasound imaging method and an ultrasound imaging apparatus, capable of producing a signed echogram reflecting the acoustic impedance of an object to be imaged by use of an ultrasound pulse that uses the entire bandwidth of an ultrasound transducer without sacrificing an excellent distance resolution made possible by the use of the ultrasound pulse.SOLUTION: With a natural number n, an ultrasound pulse having the center frequency of nf0 is transmitted, and an echo wave produced by the reflection at an acoustic-impedance interface within the object to be examined is received. Also, an ultrasound pulse having the center frequency of (n+1)f0 is transmitted, and, similarly, an echo wave produced by the reflection at the acoustic-impedance interface within the object to be examined is received. Then, by raising a received echo signal which has the center frequency of nf0 to the power of (n+1) in a multiplier 41 and also raising the received echo signal having the center frequency of (n+1)f0 to the power of n in a multiplier 42, a signal having a center frequency of n(n+1)f0is produced by both. A signed echo signal is obtained by phase-sensitive detection between the two obtained signals.COPYRIGHT: (C)2009,JPO&INPIT【課題】超音波送受信器の帯域幅をフルに使った超音波パルスを用い、それによって可能となる優れた距離分解能を損なうことなく、撮像対象の音響インピーダンスを反映した符号付きエコー像を生成可能とする超音波撮像方法及び超音波撮像装置を提供する【解決手段】nを自然数とするとき、まず、周波数nf0を中心周波数とする超音波パルスを送波して、検査対象中の音響インピーダンス界面により反射されて生ずるエコー波を受信し、また、周波数(n+1)f0を中心周波数とする超音波パルスを送波して、同じく、検査対象中の音響インピーダンス界面により反射されて生ずるエコー波を受信する。次に、周波数nf0を中心周波数とする受信エコー信号を乗算器41で(n+1)乗し、また、周波数(n+1)f0を中心周波数とする受信エコー信号を乗算器42でn乗することにより、ともに周波数n(n+1)f0を中心周波数とする信号を得る。得られた両信号の間で位相敏感検波を行うことにより、符号付きエコー信号を得る。【選択図】図6
