Which method is useful for obtaining a good quality pulmonary vein spectral Doppler waveform for...

Comprehensive and Detailed Explanation From Exact Extract:

Pulmonary vein Doppler signals have low velocity and low frequency components that can be filtered out by standard Doppler wall filters. To obtain a good quality spectral Doppler waveform for diastolic function evaluation, the wall filter settings should be lowered or adjusted to allow low frequency signals to be detected and displayed clearly.

Non-imaging transducers and continuous wave Doppler are not appropriate for pulmonary vein Doppler because spatial resolution and site localization are required. Filtering out low frequency signals would degrade the quality of the pulmonary vein waveform.

This is detailed in ASE Doppler imaging and diastolic function assessment protocols【12:ASE Diastolic Function Guidelines†p.85-90】【16:Textbook of Clinical Echocardiography, 6e†p.125-130】.