Circulation, Vol 89, 2141-2149, Copyright © 1994 by American Heart Association
PH Fan, A Anayiotos, NC Nanda, AP Yoganathan and EG Cape
BACKGROUND: Color Doppler flow mapping is widely used as a marker of
severity of valvular regurgitation, and the transesophageal approach has
provided high-quality images in patients with poor acoustic windows.
However, different instruments produce significantly variable images.
Techniques that use jet spatial information to determine the severity of
the lesion may need to be derived specifically for the instrument used.
Given a lack of standardization of the many commonly used instruments, the
goal of this study was to quantify variability between instruments by
imaging well-defined jet flow fields created in vitro. METHODS AND RESULTS:
Pulsatile jets were created in vitro using a blood analogue fluid through
physiological orifice diameters and imaged from a distal window using six
commonly used color Doppler instruments. Transesophageal transducers (5.0
MHz) were used with all instruments studied. Peak jet areas were
planimetered and averaged with systematic variations in Nyquist limit,
color filter, and sector angle (which produced variations in frame rate).
Changes in instrument settings produced significant variation in jet size
for all instruments studied. Comparisons within instruments and among
instruments were difficult because of preset and ambiguous setting levels.
When comparisons were possible between similar settings, variability was
dramatic (eg, 57% variability between instruments with very similar Nyquist
limits). CONCLUSIONS: A lack of standardized color Doppler instrument
settings prohibits translation of jet area techniques from one instrument
to another. This should be taken into consideration when using different
machines for clinical study.
ARTICLES
Intramachine and intermachine variability in transesophageal color Doppler images of pulsatile jets. In vitro studies
Heart Station Laboratory, University of Alabama at Birmingham 35233.