Evaluation of the potential of Real-Time 3-Dimensional echocardiography in the assessment of right ventricular function in patients with congenital heart disease: comparison of RT-3D echo with MRI.

Right ventricular dysfunction as a clinical problem occurs frequently in the
population of patients with congenital heart disease. Consequently, periodical
assessment of right ventricular function is indicated in a large proportion of
the patients with congenital heart disease. So far, MRI is the method of choice
for assessment of right ventricular function. The current MRI technique has
several disadvantages for its use for assessment of right ventricular function
in patients with congenital heart disease: the acquisition time for cardiac MRI
is long (30- 60 minutes) and off-line analysis is very time consuming (often >
1 hour). Both acquisition and analysis require expert knowledge in the field of
congenital heart disease, an expertise not commonly available and hardly ever
present in a radiology department, necessitating the presence of a cardiologist
or paediatric cardiologist during the whole process of data acquisition and
analysis. Recently, transthoracic Real-Time 3-Dimensional Echocardiography (RT
3-D echo) became commercially available. RT 3-D echo has the potential to
encompass the entire right ventricle in one ultrasound dataset. It is
demonstrated that, in selected cases and in experimental setting, it is
possible to acquire the right ventricle and its volume-changes throughout the
cardiac cycle within a few heartbeats with the real-time 3-D technique.
However, there are no published data about the use of RT 3-D echocardiography
for RV volumes in unselected patients in a clinical setting. The only
(unpublished) data seems promising in this respect. If it could be demonstrated
that it is feasible to assess right ventricular function reliably by 3-D
echocardiography, an alternative for MRI becomes available, which is cheaper
and has a much shorter acquisition time.

The aim of this study is assessment of right ventricular function: a comparison
between MRI and real-time 3-D echocardiography (RT 3-D echo). We have the
following research questions:
1) Is assessment of right ventricular (RV) function with RT 3-D echo in an
optimal echo setting not inferior to assessment with MRI?
2). What is the proportion of patients in which RT 3-D echo does lead to a data
set with insufficient quality, precluding RV function analysis?
3) What is the proportion of patients/ healthy adults in which RT 3-D echo with
use of echo-contrast does lead to a data set with insufficient quality,
precluding RV function analysis?

125 patients who will undergo a MRI for assessment of right ventricular
function will have a 3-D echo study within 2 hours of the MRI examination or
patients who will undergo a regular 2-D echo will undergo both a 3-D echo and
MRI. Twenty adults patients of this group will be asked permission to use
echo-contrast. Moreover, 50 healthy adults will undergo 3-D echo and MRI and
half of them will be asked to use echo-contast. The investigators are blinded
for the results of the other examination. Two independent observers will
examine the MRI data and 2 other independent observers will analyse the echo
data.

In case the MRI takes place on clinical grounds, the time investment per
patient will be 15 minutes for the 3D echo. In case both 3D echo and MRI take
place on research grounds, the time investment will be 45-60 minutes. The use
of echo-contrast leads in 0.031% of the cases to severe side effects, so there
will always be a doctor present during the examination that can use mediction
to counteract the eventuel adverse effect.