Abstract
The three vessel view (3VV) is an integral component of fetal cardiac screening. The
evaluation of vessel size is subjective in this view. Not infrequently, however,
there can be a doubt and a need arises for objective assessment. Our aim was to clarify
which ratio (AO/PA, AO/SVC, PA/SVC) can most easily judge the 3VV. We measured the
diameter of the aorta (AO), pulmonary artery (PA) and superior vena cava (SVC) in
85 fetuses that had been diagnosed with a normal heart (NH) by the spatiotemporal
image correlation (STIC) method and calculated the AO/PA ratio, AO/SVC ratio and PA/SVC
ratio. We then calculated a similar index using an offline videotape in 15 fetuses
diagnosed with coarctation of the aorta (COA), and 15 fetuses diagnosed with Tetralogy
of Fallot (TOF). TOF excluded pulmonary atresia and absent pulmonary valve. All of
the AO/PA ratios, AO/SVC ratios and PA/SVC ratios recognized a significant difference
in the CoA, TOF and the NH groups. When we calculated the ROC curve in each CoA group
and TOF group about AO/PA ratio, AO/SVC ratio, PA/SVC ratio, AO/PA ratio showed the
highest sensitivity and specificity in the CoA group and the TOF group. When the cut-off
value of the CoA for the NH group is AO/PA ratio < 0.7, good results are obtained,
sensitivity is 100% and specificity is 90.6%. When the cut-off value of the TOF from
the NH group is AO/PA ratio > 1.2, good results are obtained, sensitivity is 100%
and specificity is 98.8%. The method to measure AO/PA ratio during heart screening
can judge the 3VV objectively. When it exceeds 0.7 < AO/PA ratio < 1.2, it is likely
to be congenital heart disease.
Keywords
Three vessel view - Fetal echocardiogram - Coarctation of the aorta - Tetralogy of
Fallot
