2005-06-01-9 3D Volume Heterotaxy, transposition, hypoplastic left heart © Jeanty www.thefetus.net/
Heterotaxy, transposition, hypoplastic left heart: 3D Volume
Tennessee Women"s Care, Nashville, TN USA
This fetal echocardiogram demonstrates the following findings:
1) Heterotaxy with the stomach on the fetal right and the heart on the fetal left
2) An atrioventricular septal defect with a large primum atrial septal defect and common atrioventricular valve, with little of that orifice committed to the hypoplastic posterior left ventricle.
3) An aorta transposed anteriorly to the large right ventricle.
4) A hypoplastic pulmonary artery arising posteriorly, which appeared to arise from the hypoplastic left ventricle. There was retrograde flow by color Doppler (not shown in the volume) consistent with critical pulmonary stenosis or pulmonary atresia.
The following appeared normal:
1) Atrial situs
2) Pulmonary veins returning to the left atrium.
3) The right superior and inferior vena cava returned to the right atrium.
4) The right ventricular wall motion was normal.
The volume of this examination can be download (32 MB)
4DFetusView (the program to open the volume) can be downloaded from TOOLS > Computer Pearls > 4DFetusView
Initially you will see a display similar to the image below. Click the INIT button:
To orient the fetus it helps using standard views. This is a matter of individual preference but I usually look at fetuses in 3D as if they were on my right site (like when I scan adults) and in the axial view I view them as from top to bottom. In the coronal view they appear seen with their abdomen on top. To do this, click the A plane then with the Z rotation turn the fetus so that the spine is at 6 o"clock. The easiest way to manipulate the rotation cursors is to click on it, then use the arrows on th keyboard to go right or left. This is smoother and less jerky then doing it by manipulating the cursor directly.
Then move the A plane by right-clicking on the image until the arrows is at the level of the spine:
Now select plane B to Z rotate the spine such as it is as horizontal as possible. Essentially what we are doing here is place the fetus from any position to a more standard and comparable position.
From the previous image you see that the head of the fetus is turning to the RIGHT of the screen instead of the left. So use the Y rotation to make it turn about 180 degrees, and you should get the image below:
The finale touch is to put the Spine in place C in as vertical a position as we can by selecting plane C and using the Z rotation again:
If I now overlay the fetus these are the position we have:
We can now start the AUTOCINE button. and press START. To me natural speed is too fast and I slow it down to 12 or 25%
Select Plane A and by moving the reference slider you can note that the stomach and heart are in opposite directions that the stomach is on the right of the fetus, that the 4 chamber view does not include the left ventricle (hypoplastic). If you slide back and forth and select the plane B, you will also note the transposition of the Aorta (arising from the anterior ventricle and giving off a brachio-cephalic vessel). The pulmonary artery is posterior and very thin.