Ultrasound diagnostic apparatus and examination method

An ultrasound diagnostic apparatus, comprising:

• processing circuitry configured to
• form a first transmission beam in each of a first plurality of directions belonging to a first direction group, the first transmission beam being formed multiple times in each of the first plurality of directions;
• form a first reception beam for each of the first transmission beams so as to perform a first scan;
• form a second transmission beam in each of a second plurality of directions belonging to a second direction group, the second transmission beam being formed multiple times in each of the second plurality of directions, after an elapse of a predetermined time from performing the first scan for the first direction group, wherein one of the second plurality of directions is interposed between an adjacent pair of the first plurality of directions and the predetermined time is based on a bloodstream velocity;
• form a second reception beam for each of the second transmission beams so as to perform a second scan;
• apply a wall filter to first reception signals obtained by the first reception beams to generate first filtered reception signals, and to second reception signals obtained by the second reception beams to generate second filtered reception signals;
• calculate bloodstream information based on the generated first and second filtered reception signals;
• and
• generate image data based on the calculated bloodstream information.