Pitfalls in Doppler evaluation of diastolic function: Insights from 3-dimensional magnetic resonance imaging

Ultrasound-Doppler assessment of diastolic function is subject to velocity errors caused by angle sensitivity and a fixed location of the sample volum e. We used S-dimensional phase contrast magnetic resonance imaging (MRT) to evaluate these errors in 10 patients with hypertension and in 10 healthy v olunteers. The single (Doppler) and triple (MRI) component velocity was mea sured at early (E) and late (A) inflow along Doppler-Like sample lines or 3 -dimensional particle traces generated from the MRI data. Doppler measureme nts underestimated MRI velocities by 9.4% +/- 8.6%; the effect on the E/A r atio was larger and more variable. Measuring early and late diastolic inflo ws from a single line demonstrated the error caused by their 3-dimensional spatial offset. Both errors were minimized by calculating the E/A ratio fro m maximal E and A values without constraint to a single line. Alignment and spatial offset are important sources of error in Doppler diastolic paramet ers. Improved accuracy may be achieved with the use of maximal E and A velo cities from wherever they occur in the left ventricle.