Echo, Fetal Echo and Advanced Imaging

Question 1

What makes echo axial resolution better

Answer 1

Higher transducer frequency

Question 2

What makes echo lateral resolution better

Answer 2

• Narrower ultrasound beam width
• Larger size probe, higher frequency and focusing

Question 3

What makes echo temporal resolution (frame rate) better

Answer 3

• Decreasing depth (less time for farthest wave to return)
• Narrowing sector
• Lower line density
• Single focal point
• Parallel beam forming

Question 4

Shortening fraction equation

Answer 4

%FS = (EDD-ESD) / EDD x 100

Question 5

Ejection fraction equation

Answer 5

%EF = (EDV-ESV) / EDV x 100

Question 6

Normal markers of diastolic function (E/A, E’, E/E’)

Answer 6

• E/A: 2
• E’ > 10
• E/E’ < 10

Question 7

Abnormal relaxation markers of diastolic function (E/A, E’, E/E’)

Answer 7

• E/A: < 1
• E’ < 10
• E/E’ < 10

Question 8

Pseudonormalization markers of diastolic function (E/A, E’, E/E’)

Answer 8

• E/A: 0.8-2
• E’ < 10
• E/E’ > 10

Question 9

Restrictive markers of diastolic function (E/A, E’, E/E’)

Answer 9

• E/A: >2
• E’ < 10
• E/E’ > 10 (usually really high)

Question 10

TEE absolute contraindications

Answer 10

• Unrepaired TEF
• Esophageal obstruction
• Poor airway control
• Uncooperative unsedated patient

Question 11

TEE relative contraindications

Answer 11

• Previous esophageal surgery with possible residual obstruction
• Esophageal varices
• Vascular ring or anomaly that could produce airway obstruction
• Severe coagulopathy
• Cervical spine injury or instability

Question 12

Stress echo indications

Answer 12

• Coronary artery disease: diagnosis/risk stratification
• Exertional dyspnea
• PH
• Mitral stenosis/insufficiency
• Aortic stenosis (LV dysfunction and low grade stenosis, use dobutamine)
• HOCM

Question 13

What does LGE on MRI show

Answer 13

• Myocardial infarction
• Fibrosis
• Myocarditis
• Endocardial fibroelastosis

Question 14

Reasons to use CT instead of MRI

Answer 14

• Contraindication to MRI (pacemaker, ICD)
• Metallic implants cause too much artifact on MRI to see structures of interest
• Sedation needed for MRI but not CT
• Critically ill or unstable patient (dissection, PE)
• Airway and lung tissue evaluation is primary
• Coronary artery stenosis

Question 15

Normal lung perfusion scan differential R to L

Answer 15

• Right 55%
• Left 45%

Question 16

Indications for lung perfusion scan

Answer 16

• PA stenosis
• Pulmonary vein stenosis

Question 17

Normal septal to free wall thickness in adolescent

Answer 17

• 1.1 (range 0.8 to 1.4)
• Increases in adult to average of 1.2

Question 18

Indications for fetal echo

Answer 18

• Familial (CHD in sib or parent)
• Maternal (DM, PKU, autoantibodies, drug exposure, rubella, assisted reproduction)
• Fetal (suspicion CHD, fetal arrhythmia, extracardiac malformations, increased nuchal thickness, genetic abnormality, single umbilical artery, twins, hydrops)

Question 19

Risks with absent ductus venosus

Answer 19

• CHD, volume overload, heart failure

Question 20

Problems with restrictive PFO

Answer 20

• RV dilation, TR, small left sided structuresP

Question 21

Problems with restrictive PDA

Answer 21

RV dilation or dysfunction, TR, neonatal PH
- Fetal echo with flow velocity > 1.4 m/s

Question 22

Most common type of tumor in kids, especially infants

Answer 22

Rhabdomyomas

Question 23

Well circumscribed, non-capsulated, intramural or intracavitary nodules that can occur anywhre in the heart

Answer 23

Rhabdomyomas
- Appear bright on echo
- Often multiple

Question 24

Presenting symptoms for cardiac myxoma

Answer 24

• Obstruction (80%)
• Embolism (70%)
• Systemic illness (60%)

Pedunculated friable masses commonly in the left atrium and can be attached to foramen ovale

Question 25

Causes of reversal of flow in descending aorta

Answer 25

• PDA
• Severe AI
• Intracranial AV malformation (Vein of Galen malformation

Question 26

How soon do microbubbles appear in left heart with agitated saline injection

Answer 26

If there is an intrapulmonary shunt it is usually in 3-5 cardiac cycles versus 1-2 cardiac cycles for intracardiac shunt

Question 27

Best echo view for secundum ASD

Answer 27

Subcostal four chamber view

Question 28

Echo findings for restrictive LV physiology

Answer 28

• Increased mitral inflow doppler E:A ratio > 2
• Shortened mitral E wave deceleration time < 160 ms
• Decreased lateral mitral Ea velocity
• Increased E/E’ ratio > 15

Question 29

Definition of nyquist limit

Answer 29

Maximal frequency shift detectably by PW doppler
Equal to 1/2 of the PRF

Question 30

Echo definitions of cardiac tamponade

Answer 30

Respiratory changes in doppler flow across tricuspid valve of > 30% and mitral valve of > 25%
Can also see diastolic right atrial and right ventricular collpase

Question 31

Most common type of VSD associated with coarctation

Answer 31

Perimembranous
Posterior malalignment

Question 32

Most reliable way to distinguish a mitral from tricuspid valve

Answer 32

Level of attachment at the crux of the heart

Question 33

Normal fetal-thoracic area ratio

Answer 33

25-35%
About 1/3

Question 34

Common causes of hypertrophy on fetal echo

Answer 34

Recipient twin in twin-twin transfusion
Fetus of diabetic mother
Fetal hypertrophic cardiomyopathy
Fetal Noonan syndrome

Question 35

What are uses for spin echo MRI technique

Answer 35

Black blood imaging - myocardium/tissue are different gray/white colors

• Imaging myocardial and blood vessel walls
• Cardiac tumors/masses
• Pericardium
  T1/T2 weighted sequences in spin echo imaging help with tissue characterization