Anomaly Scan at 16-18 weeks of pregancy

 

TIFA= Trageted /Anomaly scan what to image?? What to look for  in 2nd trimester, target anatomy .If that is the objective then
the fetus is examined on cross section, longitudinal section and coronal.
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CROSS SECTION, going down below the fetal chest, one will see:

1. Stomach (presence, size, and situs);
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2. Kidneys; If renal pelvis looks big, measure the AP diameter. If 4 mm or greater at mid gestation, the kidneys need to be re-examined at 32 weeks, for pyelectasis. 
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3. Umbilical cord insertion site into the fetal abdomen; and
Umbilical cord vessel number. The two arteries will be on either side of the fetal bladder. If both are documented, then you know it is a 3 vessel cord. The 3 vessels can also be documented on a cross section of e free loop of the cord, but if your machine has color capabilities, it makes it easy to see the arteries around the bladder.
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4. Urinary bladder; put color, for arteries on both sides (confirms that the fetus has a 3 vessel cord)
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5. The two leaves of the diaphragm can also be seen. Helps rule out diaphragmatic hernia, but it can be missed as well. So always look at the lungs when doing the 4 chamber view of the heart, on cross section of chest. 
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6. Spine, sacrum: Look at the overlying skin, make sure it is not 'broken'

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Next  LONGTIDUNAL exam and look at the:
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1. Diaphragm, left and right side
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2. Spine, longitudinal and then cross section. Look at the overlying skin, make sure it is not 'broken'
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3. Document both arms, forearms, thighs, legs, hands and feet. Hands should be seen to open and close. This becomes more important if the fetus has CPCs. Since CPCs have an association with T-18, it's good to see hands open. Fetuses with T-18 often have clenched hands, and overlapping fingers.
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CORONAL longitudinal:
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1. Lips. Move the transducer back and forth, to see the complete thickness of the lip. Also check the nares (nostrils). In most cases of cleft lips, the cleft connects with the nares, sort of 'dragging' it down.
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2. Kidneys. For duplicated system, and any other pathology 
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3. Spine. The spine may look normal on coronal or on longitudinal. therefore it is important to look at it in cross section/longitudinal/coronal. Always look at the skin on the back of the sacrum. NTDs are most common in lumbosacral region. Even when the NTD is small, the cerebellum / cisterna magna will look abnormal in ~97% of NTDs.