How automated techniques ease functional assessment of the fetal heart:
applicability of two-dimensional speckle-tracking echocardiography for
comprehensive analysis of global and segmental cardiac deformation using
fetalHQ®
Abstract
Background Prenatal echocardiographic assessment of fetal
cardiac function has become increasingly important. Fetal
two-dimensional speckle-tracking echocardiography (2D-STE) allows the
determination of global and segmental functional cardiac parameters.
Prenatal diagnostics is relying increasingly on artificial intelligence,
whose algorithms transform the way clinicians use ultrasound in their
daily workflow. The purpose of this study was to demonstrate the
feasibility of whether less experienced operators can handle and might
benefit from an automated tool of 2D-STE in the clinical routine.
Methods A total of 136 unselected, normal, singleton, second-
and third-trimester fetuses with normofrequent heart rates were examined
by targeted ultrasound. 2D-STE was performed separately by beginner and
expert semiautomatically using a GE Voluson E10 (FetalHQ®, GE
Healthcare, Chicago, IL, USA). Several fetal cardiac parameters were
calculated (end-diastolic diameter (ED), sphericity index (SI), global
longitudinal strain (EndoGLS), fractional shortening (FS)) and assigned
to gestational age (GA). Bland-Altman plots were used to test agreement
between both operators. Results The mean maternal age was 33
years, and the mean maternal body mass index prior to pregnancy was
24.78 kg/m 2. The GA ranged from 16.4 to 32.0 weeks
(average 22.9 weeks). Averaged endoGLS value of the beginner was -18.57
% ± 6.59 percentage points (pp) for the right and -19.58 % ± 5.63 pp
for the left ventricle, that of the expert -14.33 % ± 4.88 pp and
-16.37 % ± 5.42 pp. With increasing GA, right ventricular endoGLS
decreased slightly while the left ventricular were almost constant. The
statistical analysis for endoGLS showed a Bland-Altman-Bias of -4.24 pp
± 8.06 pp for the right and -3.21 pp ± 7.11 pp for the left ventricle.
The Bland-Altman-Bias of the ED in both ventricles in all analyzed
segments ranged from -0.49 mm ± 1.54 mm to -0.10 mm ± 1.28 mm, that for
FS from -0.33 pp ± 11.82 pp to 3.91 pp ± 15.56 pp and that for SI from
-0.38 ± 0.68 to -0.15 ± 0.45. Conclusions Between both
operators, our data indicated that 2D-STE analysis showed excellent
agreement for cardiac morphometry parameters (ED and SI), and good
agreement for cardiac function parameters (EndoGLS and FS). Due to its
complexity, the application of fetal 2D-STE remains the domain of
scientific-academic perinatal ultrasound and should be placed preferably
in the hands of skilled operators. At present, from our perspective, an
implementation into clinical practice ‘on-the-fly’ cannot be
recommended.