Ultrasound Basics Step 5 Step 5 (1 hour) Complete the Self Learning Pre-Tests Modes & Probes - Dopler Self Test 1. What is Doppler ultrasound used for?Measure cardiac dimensions over timeAddition to 2D echo by filtering artifactsAddition to 2D echo by harmonicDetect presence, speed, and direction of blood flowBased on Doppler principle, when a sound source moves away from an observer, the frequency will:DecreaseIncreaseStay the sameCannot be determinedA positive Doppler shift means:Red blood cells are moving towards probeRed blood cells are moving away from probeRed blood cells are not movingDoppler information is most accurate when angle of ultrasound beam and moving object is:PerpendicularParallelAny angleT or F: On color flow, arterial blood is always red and venous is always blue.TrueFalse