Comparison of Two Different Ultrasound Systems for the Evaluation of Tissue Doppler Velocities in Fetuses.
BACKGROUND
Recent studies have reported variations of up to 30% between different ultrasound machines for tissue Doppler imaging (TDI), a problem that can significantly impact clinical diagnosis, patient management and research studies. The objective of this study was to assess repeatability and agreement between fetal myocardial peak velocities evaluated by TDI with two different ultrasound systems.


METHODS
Systolic (S'), early (E') and late (A') diastolic myocardial peak velocities at mitral and tricuspid annuli as well as at the basal septum were evaluated by spectral TDI in 150 fetuses using two different ultrasound systems: Siemens Antares (Siemens Medical Systems, Malvern, Pa., USA) and Vivid Q (General Electric Healthcare, Horten, Norway). A method comparison study was performed, calculating intraclass correlation coefficients (ICC), and agreement was assessed by Bland-Altman plots.


RESULTS
Annular peak velocities showed lower values when measured by Vivid Q compared to values measured by Siemens Antares. ICC ranged from 0.07 (septal S') to 0.33 (right A'), showing very poor repeatability for clinical application. Agreement between the two systems was also poor, with high coefficients of variation for all measurements.


CONCLUSIONS
Fetal annular peak velocities obtained with different ultrasound systems are not directly comparable. This is consistent with previous data in adults and warrants the need of system-specific reference values, suggesting that the same ultrasound machine should be used for longitudinal follow-up.
BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clx00ED;nic and Hospital Sant Joan de Deu), Barcelona, Spain.
Mónica
M
Cruz-Lemini
Brenda
B
Valenzuela-Alcaraz
Francesc
F
Figueras
Marta
M
Sitges
Olga
O
Gómez
Josep María
JM
Martínez
Bart
B
Bijnens
Eduard
E
Gratacós
Fátima
F
Crispi
D000328:Adult; D015150:Echocardiography, Doppler / Q000295:instrumentation / Q000592:standards*; D005260:Female; D005333:Fetus / Q000000981:diagnostic imaging*; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D011247:Pregnancy; D012016:Reference Values; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000295:instrumentation / Q000592:standards*