Subject information acquisition apparatus, subject information acquisition method, and program

A subject information acquisition method for acquiring pressure information on inside of a left ventricle of a subject, the method comprising:

• transmitting acoustic waves to the subject into which contrast medium has been introduced;
• receiving acoustic waves from the subject into which the contrast medium has been introduced, and outputting receiving signals including at least a first receiving signal and a second receiving signal, the first receiving signal based on an acoustic wave during a left ventricular systole and the second receiving signal based on an acoustic wave during the left ventricular end-dilation;
• acquiring the receiving signals based on the acoustic waves from a left ventricle of the subject into which the contrast medium has been introduced, during each of the left ventricular systole and the left ventricular end-dilation, the left ventricular end-dilation having a different pressure inside the left ventricle from that of the left ventricular systole;
• acquiring pressure information obtained from an upper arm of the subject during the left ventricular systole;
• acquiring information regarding a presence concentration of the contrast medium within the left ventricle based on the first receiving signal and pressure information obtained, by a blood pressure measurement unit, from the upper arm during the left ventricular systole;
• and
• determining pressure information on the endocardial pressure inside the left ventricle of the subject during the left ventricular end-dilation based on the second receiving signal and the information regarding the presence concentration of the contrast medium within the left ventricle.

A subject information acquisition apparatus comprising:

• a converter configured to receive acoustic waves from a subject into which contrast medium has been introduced, and to output receiving signals including at least a first receiving signal and a second receiving signal, the first receiving signal based on an acoustic wave during a left ventricular systole and the second receiving signal based on an acoustic wave during the left ventricular dilation;
• and
• a pressure information acquisition unit configured to acquire pressure information on endocardial pressure inside a left ventricle of the subject,
• wherein the pressure information acquisition unit acquires information regarding a presence concentration of the contrast medium within the left ventricle based on the first receiving signal and pressure information on a blood pressure of an aortic root during the left ventricular systole, and
• wherein the pressure information acquisition unit determines pressure information on the endocardial pressure inside the left ventricle during the left ventricular dilation based on the second receiving signal and the information regarding the presence concentration of the contrast medium within the left ventricle.