QUANTITATION OF LEFT TO RIGHT SHUNT IN
CHINDREN WITH VENTRICULAR SEPTAL DEFECT USING 3D VOLUMETRIC COLOR FLOW
MAPING
Kai-Sheng
Hsieh, Yu-Hsiang Chang, Cheng-Liang Lee, Ta- Cheng Huang
Dept. of
Pediatrics, Veterans General Hospital, Kaohsiung, Chinese Taipei
Background: Most up-to-date echocardiography machines
are equipped with Color Doppler Flow Mapping for evaluation of
cardiovascular flow pattern. But the calculation of flow volume, such as
degree of shunt, is largely based on estimation. This study used a novel 3D
volumetric calculation platform to quantitate the left-to-right shunt in
children with VSD.
Materials and Methods: Ten children, aged 3
days to 3.9years,with VSD were enrolled in this study. After standard
procedure for CDFM, 3D volumetric color flow images of left-to-right shunt
were obtained from free hand stepwise transthoracic 2D scanning. Real-time
3D blood flow can be displayed isolatedly or superimposed on 3D tissue
images. Disc summation used to calculate the flow jet volume, The
pulmonary-to-systemic flow ratio could be derived by area-flow calculation
from pulmonary and aortic roots respectively. Three parameters were
derived: Total shunt volume (TSV, volume summation of systolic jets in all
phases of a cardiac cycle); Maximal shunt volume (MXSV, the systolic jet of
largest volume in a cardiac cycle); and Mean shunt volume (MSV,TSV divided
by number of phases in a cardiac cycle).
Result: 3D CDFM could be satisfactorily displayed and
VSD jets quantified Linear regression method was used to compare the shunt
volumes derived from conventional area-flow method and those from 3D
acquisition methods, p-values, coefficients of regression, standard errors
were tabulated
as below:
A (ml) b x (ml) S.E.E(ml) r2 p
-0.553 6.877MxSV 0.831 0.69 0.03
0.878 0.711TSV 0.929 0.863 <0.01
0.29 22.043MSV 0.905 0.9818
<0.001
Conclusions: The
free-hand image acquisition method and novel 3D reconstruction alogorithm
of CDFM images provided an optimal way of shunt volume measurement in
children with VSD. Errors from geometric or flow profile assumptions could
be avoided.
