Question: List the approaches to quantitation of regurgitant severity. Discuss the Etiology of Valvular Regurgitation. Describe how Color Doppler is used to assess Valvular Regurgitation. Clarify how Spectral Doppler waveforms appear in regurgitant lesions? What are your responsibilities as a Sonographer in imaging these pathologies? paragraph form and 600 words. Want Professional Help?