Ch 15 Soft Markers

Question 1

What are soft markers?

Answer 1

Sonographic findings that are generally not abnormalities, but are indicative of an increased age adjusted risk for an underlying fetal aneuploidic or non-chromosomal abnormality

Question 2

Do most soft markers constitute (form) a structural defect?

Answer 2

No - the soft markers may be detected on antenatal screening, m/c during 2nd trimester anatomy scan

Question 3

Are many soft markers transient?

Answer 3

Yes! Meaning they only last for a short time

Question 4

List 10 things that increase the risk for aneuploidy?

Answer 4

-NF over 6mm
-Ventriculomegaly over 10mm
-Hypoplastic or absent NB
-Echogenic intracardiac focus (EIF)
-Choroid plexus cysts
-Echogenic bowel
-Shortened long bones (less than 3rd percentile)
-Shortened femur (femur/foot ratio)
-Shortened humerus
-Aberrant rt subclavian artery

Question 5

List 3 things that increase the risk of a non-chromosomal abnormality?

Answer 5

-Pyelectasis (renal pelvic dilatation) over 5mm
-Single umbilical artery (SUA)
-Enlarged cisterna magna

Question 6

List 4 undefined soft markers?

Answer 6

-Clenched fists (does not open hands in exam)
-Rocker bottom feet (curvy souled feet)
-Sandal gap (gap b/w big toe + 2nd toe)
-Strawberry shaped skull

Question 7

How many times must we measure soft markers?

Answer 7

Just once

(take the echogenic cardiac focus in 2 planes tho)

Question 8

How to obtain NF measurement?

Answer 8

-TRV head at level of CSP, thalami + cerebellum (angle posterior to include cerebellum)

-Take measurement from outer edge of occiput bone to outer skin limit directly in the midline

Question 9

When is the NF measurement considered significant?

Answer 9

18-24 weeks = >6mm (m/c)

16-18 weeks = >5mm

Question 10

List the nuchal index formula?

Answer 10

Nuchal thickness (mm) / BPD (mm)

Question 11

Which bowel echogenicity grades are significant?

Answer 11

Bowel equal to bone (grade 2) OR greater than bone (grade 3) is significant

(grade 1, less than bone, is not significant and should not be reported)

Question 12

How should echogenic bowel be identified?

Answer 12

By comparing the echogenicity of bowel with the echogenicity of bone

(use 5 MHz probe or less + use appropriate gain setting)

Question 13

What is considered mild ventriculomegaly?

Answer 13

B/w 10-15mm

Question 14

How can we obtain a correct LV measurement?

Answer 14

-From axial plane at level of thalamic nuclei, just below image to measure the BPD
-Measure the ventricle that is in the far field (posterior one), due to artifacts in near field one
-Calipers are placed perpendicular to long axis of ventricle, at edges of lumen, near the posterior portion of choroid plexus

Question 15

What does EICF stand for?

Answer 15

Echogenic intracardiac focus

(it is a focus of echogenicity as bright as bone located in the heart)

Question 16

In what position of the heart are EICFs m/c diagnosed in?

Answer 16

4CH

(use 5 MHz probe or less + appropriate gain to diagnose, do NOT report if not as bright as bone)

Question 17

What measurement classifies a choroid plexus cyst?

Answer 17

Over 3mm

Question 18

During what weeks are CP cysts found?

Answer 18

B/w 14-24 weeks

(found in CP within the lateral cerebral ventricles)

Question 19

How do we image the CP?

Answer 19

In TRV plane of head at same level as the LV is evaluated

Question 20

What measurement defines an enlarged cisterna magna?

Answer 20

An anterior/posterior diameter of >10mm

(measurement will be falsely exaggerated by a steep scan angle through posterior fossa OR dolichocephaly)

Question 21

How do we correctly measure the cisterna magna?

Answer 21

-A transaxial view of head angled 15 degrees caudal to canthomeatal line

-Anterior/posterior diameter taken b/w the inferior/posterior surface of vermis of cerebellum to inner surface of cranium

Question 22

What is mild pyelectasis defined as?

Answer 22

A hypoechoic spherical or elliptical space within renal pelvis that measures b/w 5-10mm

Question 23

How to obtain a correct measurement of pyelectasis?

Answer 23

Take on TRV section through renal pelvis using the max anterior-posterior measurement

Question 24

Are measurements <5mm normal for a renal pelvis?

Answer 24

Yes! Do not call + report this as pyelectasis!

(ex. if pelvis measures 4.8mm, do not round up to 5mm + make it abnormal)

Question 25

What is SUA?

Answer 25

-Single umbilical artery
-Absence of 1 of the umbilical cord arteries surrounding the fetal bladder

(cord only contains 1 vein + artery, if we see this must look for other abnormalities)

Question 26

What is defined as a short NB?

Answer 26

Is defined by the chart your site uses, must check the site

Question 27

How do we properly measure the foot?

Answer 27

From longest toe to heel

Question 28

A sandal toe/gap may be an indicator of what?

Answer 28

Aneuploidy - m/c down syndrome

(note on tech sheet if seen)

Question 29

If a fetus has ventriculomegaly, where will the pt get referred to in BC?

Answer 29

FDS or Victoria MFM

Question 30

If a fetus has an absent NB, increased NF or echogenic bowel, where will the pt get referred to in BC?

Answer 30

Medical genetics Vancouver or Victoria

Question 31

If a fetus has EICF, pyelectasis or abnormal femur/foot ratio, where will the pt get referred to in BC?

Answer 31

Non-Isolated: medical genetics vancouver or victoria

Isolated: multiple options available (chart in slide)

Question 32

If a fetus has choroid plexus cysts, where will the pt get referred to in BC?

Answer 32

IUGR or abnormality present: medical genetics vancouver or victoria

No IUGR or abnormality present: multiple options available (chart in slide)

Question 33

What is the upper limit of normal for fetal pyelectasis?

Answer 33

4.9mm

Question 34

What must an EICF demonstrate to be considered a soft marker?

Answer 34

As bright as bone

Question 35

What defines grade 2 echogenic bowel?

Answer 35

Bowel is equal to bone in brightness

Question 36

What defines grade 3 echogenic bowel?

Answer 36

Bowel is brighter than bone

Question 37

What defines grade 1 echogenic bowel?

Answer 37

Bowel is less bright than bone

(this grade is normal + not a soft marker)