Question Answer
What is the most dependent space for fluid in females? Rectouterine pouch
What is the most dependent space for fluid in males? Rectovesical pouch
Where does free fluid collect in females? Rectouterine pouch (Pouch of Douglas)
Can FAST differentiate between types of fluid? No, it only detects presence of fluid
What ultrasound finding rules out pneumothorax? Lung sliding or seashore sign on M-mode
What cardiac chamber collapses in systole with tamponade? Right atrium
What is the correct next step for traumatic pericardial tamponade? Emergent thoracotomy
What sign is 100% specific for pneumothorax? Lung point
What is the normal aortic diameter on ultrasound? < 3 cm
What structure helps differentiate RV from LV in A4C? Moderator band or apical offset of tricuspid valve
What does the apical offset of the AV valves help identify? RV vs LV in A4C view
How to Differentiate the LV from the RV
1. Wall Thickness
| LV | RV |
|---|---|
| Thick, muscular walls | Thin walls |
-
The RV is thinner and more compliant.
2. Location & Shape
| LV | RV |
|---|---|
| Bullet- or ellipse-shaped | Crescent- or triangle-shaped |
| Extends to apex | Wraps partially around LV |
-
The RV is more anterior, triangular, and does not reach as far toward the apex.
3. Apical Valve Insertion ("Apical Offset")
-
The tricuspid valve (RV) inserts closer to the apex than the mitral valve (LV).
-
This creates an "offset" seen clearly in A4C view.
Mnemonic: “Tricuspid is Taller” → inserts more apically.
4. Trabeculations
| LV | RV |
|---|---|
| Smooth endocardium | Coarse trabeculations |
-
The LV is generally smooth-walled.
5. Moderator Band
-
Found only in the RV.
-
Appears as a bright, linear echogenic band crossing the RV cavity.
6. Outflow Tracts & Valve Orientation
-
Parasternal Long Axis (PLAX):
-
LV is the primary chamber seen
-
RV appears as a thin, anterior crescent
-
-
PLAX view includes aortic valve outflow from the LV, not RV
Summary Table
| Feature | Left Ventricle (LV) | Right Ventricle (RV) |
|---|---|---|
| Wall thickness | Thick | Thin |
| Shape | Bullet / Elliptical | Crescent / Triangular |
| Apex reach | Extends to apex | Does not extend to apex |
| Valve insertion | More basal (higher) | More apical (lower) |
| Trabeculations | Smooth | Coarse |
| Moderator band | Absent | Present |
| Outflow direction (PLAX) | Toward aortic valve | Not visualized in this plane |
What view shows Morison's pouch? RUQ (Right Upper Quadrant)
What are the core components of the RUSH exam? Cardiac, IVC, Aorta, E-FAST
HIMAP
At what size is a gestational sac considered anembryonic? ≥ 25 mm with no embryo
What does gain that's too high do to fluid appearance? Can obscure anechoic fluid by making the image too bright
What is the normal aortic diameter on ultrasound? < 3 cm
What are B-lines? Vertical comet tails indicating interstitial fluid
When is the e-FAST exam complete? When RUQ, LUQ, pelvic, subxiphoid heart, and both anterior lungs are imaged
Can B-lines be normal? Yes, especially at the lung bases in healthy individuals
At what size is a gestational sac considered anembryonic? ≥ 25 mm with no embryo
Where does free fluid collect in males? Rectovesical pouch
What is a positive FAST exam? Free fluid in RUQ, LUQ, pelvis, or pericardium
What are signs of fluid overload on ultrasound? B-lines, plethoric IVC, decreased EF
What does anechoic mean? No echoes — appears black
What does the RUSH exam assess? Cause of hypotension/shock using POCUS
What is the most dependent space for fluid in females? Rectouterine pouch
What is a positive FAST exam? Free fluid in RUQ, LUQ, pelvis, or pericardium
What is McConnell’s sign on cardiac ultrasound? Hypokinetic RV free wall with hyperdynamic apex
What does EPSS < 7 mm indicate? LVEF < 30%
A second study derived a similar equation and correlation and demonstrated 100% sensitivity of an EPSS measurement > 7mm for detecting severely reduced EF (<30%)
- McKaigney CJ, Krantz MJ, La Rocque CL, Hurst ND, Buchanan MS, Kendall JL. E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction. Am J Emerg Med. 2014;32(6):493-497.
Is trace free fluid normal in trauma patients? No, especially not in Morison's pouch
What are the core components of the RUSH exam? Cardiac, IVC, Aorta, E-FAST
Can FAST differentiate between types of fluid? No, it only detects presence of fluid
What is the seashore sign? Normal lung M-mode with lung sliding
What does a plethoric IVC mean in hypotension? Likely obstructive or cardiogenic shock
What does a non-collapsing IVC suggest? Tamponade or volume overload
What is a hallmark of tamponade on ultrasound? Pericardial effusion + RA or RV collapse
What is the first view typically performed in FAST? RUQ
What does a non-collapsing IVC suggest? Tamponade or volume overload
What is the aortic root considered dilated? > 4 cm
What does RV:LV ≥ 1 in A4C view suggest? RV dilation or strain (e.g., PE)
What is the seashore sign? Normal lung M-mode with lung sliding
What cardiac chamber collapses in diastole with tamponade? Right ventricle
What ultrasound finding rules out pneumothorax? Lung sliding or seashore sign on M-mode
What is a hallmark of tamponade on ultrasound? Pericardial effusion + RA or RV collapse
How many views are in e-FAST? 7: RUQ, LUQ, bladder (2), heart, and 2 lung apices
What does RV:LV ≥ 1 in A4C view suggest? RV dilation or strain (e.g., PE)
Where does free fluid collect in females? Rectouterine pouch (Pouch of Douglas)
What sign is 100% specific for pneumothorax? Lung point
What is the D sign in cardiac ultrasound? Flattened septum in PSAX view indicating RV pressure overload
Where does free fluid collect in males? Rectovesical pouch
At what size is a gestational sac considered anembryonic? ≥ 25 mm with no embryo
What is the most reliable view to detect tamponade? Subxiphoid cardiac view
What cardiac chamber collapses in systole with tamponade? Right atrium
Where does free fluid collect in males? Rectovesical pouch
What are the pelvic views in e-FAST? Bladder in transverse and sagittal
What is the most dependent space for fluid in males? Rectovesical pouch
What does the parasternal long view assess? LV function, pericardial effusion, aortic root
When is CT contraindicated in trauma? Hemodynamic instability with positive FAST
What is McConnell’s sign on cardiac ultrasound? Hypokinetic RV free wall with hyperdynamic apex
What is the first view typically performed in FAST? RUQ
What does gain that's too low do to ultrasound images? Can make anechoic fluid appear invisible or too dark
What does the apical offset of the AV valves help identify? RV vs LV in A4C view
What is the D sign in cardiac ultrasound? Flattened septum in PSAX view indicating RV pressure overload
What measurement suggests an interstitial ectopic pregnancy? Myometrial mantle < 7 mm
What view shows Morison's pouch? RUQ (Right Upper Quadrant)
What is the correct next step for traumatic pericardial tamponade? Emergent thoracotomy
What does LVH look like on ultrasound? LV wall > 1.2 cm in diastole
What are signs of fluid overload on ultrasound? B-lines, plethoric IVC, decreased EF
What are B-lines? Vertical comet tails indicating interstitial fluid
What does LVH look like on ultrasound? LV wall > 1.2 cm in diastole
What is the most reliable view to detect tamponade? Subxiphoid cardiac view
What confirms an intrauterine pregnancy (IUP)? Gestational sac + yolk sac or fetal pole
What does the sandy beach sign indicate? Normal lung sliding on M-mode
What confirms an intrauterine pregnancy (IUP)? Gestational sac + yolk sac or fetal pole
Can B-lines be normal? Yes, especially at the lung bases in healthy individuals
What does a plethoric IVC mean in hypotension? Likely obstructive or cardiogenic shock
What is the aortic root considered dilated? > 4 cm
How many views are in e-FAST? 7: RUQ, LUQ, bladder (2), heart, and 2 lung apices
What measurement suggests an interstitial ectopic pregnancy? Myometrial mantle < 7 mm
What measurement suggests an interstitial ectopic pregnancy? Myometrial mantle < 7 mm
What does a collapsing IVC suggest? Hypovolemia
Is trace free fluid normal in trauma patients? No, especially not in Morison's pouch
What does a collapsing IVC suggest? Hypovolemia
What does anechoic mean? No echoes — appears black
What does EPSS ≥ 7 mm indicate? LVEF < 30%
What cardiac chamber collapses in diastole with tamponade? Right ventricle
When is the e-FAST exam complete? When RUQ, LUQ, pelvic, subxiphoid heart, and both anterior lungs are imaged
What confirms an intrauterine pregnancy (IUP)? Gestational sac + yolk sac or fetal pole
What are the pelvic views in e-FAST? Bladder in transverse and sagittal
When is CT contraindicated in trauma? Hemodynamic instability with positive FAST
What does the barcode sign on lung ultrasound indicate? Pneumothorax
What does the sandy beach sign indicate? Normal lung sliding on M-mode
What does the barcode sign on lung ultrasound indicate? Pneumothorax
What does gain that's too low do to ultrasound images? Can make anechoic fluid appear invisible or too dark
Where does free fluid collect in females? Rectouterine pouch (Pouch of Douglas)
What does the RUSH exam assess? Cause of hypotension/shock using POCUS
What does gain that's too high do to fluid appearance? Can obscure anechoic fluid by making the image too bright
What does the parasternal long view assess? LV function, pericardial effusion, aortic root
und finding rules out pneumothorax? Lung sliding or seashore sign on M-mode
The moderator band is a distinctive muscular structure found only in the right ventricle (RV) — and it’s a very useful landmark on cardiac ultrasound for identifying the RV.
Moderator Band – Key Facts
What is it?
-
A muscular band of heart tissue
-
Connects the interventricular septum to the anterior papillary muscle in the right ventricle
-
Carries part of the right bundle branch (for conduction)
Why is it important in ultrasound?
-
It helps you differentiate the RV from the LV
-
If you see a bright, linear echogenic band crossing a ventricular chamber, and the chamber looks thin-walled, trabeculated, and more anterior → it’s the right ventricle
-
Most easily seen in the apical 4-chamber (A4C) view
How it looks on ultrasound:
-
A thin bright line crossing the RV cavity
-
Often seen in the mid to distal RV, near the apex
-
May resemble a chord or bridge
Clinical tip:
If you're unsure whether a chamber is LV or RV, spotting the moderator band confirms it's the RV.
Summary:
The moderator band is a muscle band unique to the right ventricle, visible on echo, that helps identify RV anatomy and participates in electrical conduction.
Comments
Post a Comment