Normal spectral Doppler waveform in a low resistance artery
Flow within arteries supplying organs that require constant perfusion include arteries to the brain, liver, and kidneys. The waveforms in these arteries will have continuous monophasic forward flow toward the organ throughout diastole. They have broad systolic peaks, gradual transition between systole and diastole, and persistent diastolic flow. Low-resistance vessels will also have low RIs.