Fetal Diagnosis Imaging: Fetal Genitourinary Disease 2015

Amnioinfusion is needed if the patient is a candidate for a shunt in order to place the shunt properly

A karyotype can usually be obtained from a washing of the amniotic sac by doing amnioinfusion

Amnioinfusion allows visualization of the uncompressed chest to look at chest size and compare it to norms, which can help predict pulmonary hypoplasia

Ratios of heart size relative to chest are very critical in prognoses for fetal bladder outlet obstruction

Associated anomalies of the heart are not common in fetal genitourinary disease

After intervention, if fluid volume drops off again because of end-stage fetal renal disease, amnioinfusions can be repeated through several different techniques

Bladder outlet obstruction diagnosis was made in the mid-trimester to early 3rd trimester in the past, but is now able to be diagnosed very early in gestation, just outside of the first trimester

The keyhole configuration of the bladder is seen commonly with posterior urethral valves or other obstructive neuropathies

When evaluating kidneys in bladder outlet obstruction, assessment should include echogenicity of the parenchyma and orientation of renal cysts to predict postnatal renal function

Early in the disease process, renal cysts can be distributed around the outer pole of the kidney, and as the process progresses, things become more disoriented and distorted

Fetal genitourinary disease is not just isolated to the genitourinary system; evaluation must include looking for a variety of other abnormalities

With oligohydramnios, the problem comes back to pulmonary hypoplasia, and if pulmonary hypoplasia is in place, it is very difficult to correct

A bell-shaped thorax with lower ribs being pushed out indicates the pulmonary circuit is not developing normally

If kidneys are high enough or big enough that they are impairing diaphragmatic excursion, there is a bigger problem and more likely diagnosis of pulmonary hypoplasia

Data on phrenic nerve dissection shows loss of diaphragmatic movement as a primary reason for pulmonary hypoplasia; big kidneys can cause the diaphragm to stop moving and create the same crisis for pulmonary development

For fetal genitourinary disease, MRI provides a very real opportunity to give parents a visual image that they can better get a handle on the diagnosis

For renal abnormalities, MRI is a very important discriminator because it gives a big picture of the baby and the images are clear for parents to see