Ch 11 Subcostal Flashcards
List the subcostal imaging planes?
-4CH* (5CH, RVOT)
-IVC/Hep vein*
-Abdominal Ao*
-SAX (AoV, MV, PM, apex)
-Bicaval
-Situs
(* = routinely performed)
How should the pt lie for subcostal scanning?
In supine with legs bent at knees (to relax abdominal wall musculature)
What should pt’s m/c do with their breathe during subcostal scanning?
Breath in + hold m/c improves image
Is this window helpful in FAST exams?
Yes! Also helpful with pt’s who have suboptimal parasternal/apical windows
What is the subcostal window used to assess?
The heart, pericardium, RV free wall thickness + extracardiac vasculature
What are some reasons a pt may have suboptimal parasternal or apical windows?
-Heart sits low in chest
-Too much lung in the way
Where do we put our probe + indicator for subcostal 4CH?
-Probe placed on pt’s abdomen, under xiphoid process
-Probe tilted slightly leftward
-Indicator points to pt’s left side at 3 o’clock
Do we need to see the LV apex in our SUB 4CH view?
No, it is nice if we can see it but apical views are better to assess the apex
What is the best standard view to quickly assess for pericardial effusion + septal defects?
SUB 4CH - b/c septum is perpendicular to the u/s beam
(septal defects: ASDs, VSDs, patent foramen ovale)
What can cause RV + LV hypertrophy?
RV: pulmonary hypertension
LV: systemic hypertension
What structures are seen in SUB 4CH?
-LA
-MV
-LV
-RA
-TV
-RV
-IVS
-IAS (zoomed in clips allow assessment for PFO + ASD)
The RV free wall when measured at peak of R wave in line with the tip of the anterior TV leaflet when open should be less than how many mm to be considered normal?
<5mm = normal
What are 2 other views we can get from SUB 4CH?
-5CH (angle anteriorly)
-RVOT (angle even more anteriorly)
How can we acquire the zoomed in IAS from SUB 4CH?
-Decrease depth + zoom into IAS
-Acquire a clip + then evaluate same area with CD
-Perform tiny sweeps to ensure we have evaluated entire IAS
Should we increase or decrease our scale when evaluating the IAS?
-Decrease it to 30-50 (depending on pt’s HR) to allow for lower flow to be seen
-Higher HR means set a higher scale
(should not see any flow crossing the IAS in a normal pt)
What is the m/c type of ASD?
Secundum ASD
(must seek the skinny legend when imaging IAS to ensure we have fully evaluated it)
Do shunts go from left-right or right-left?
Left to right b/c they go to an area of less pressure
How can we optimize our SUB 4CH?
-Get pt to take big breath in + hold it
-Rotate slightly clockwise or counter-clockwise to see all 4 chambers
-Rock (heel/toe) to center heart
-Move slightly to pt’s right + angle superiorly or inferiorly
For the most part we want a horizontal + flat 4CH, when would we want a more vertical 4CH?
-To assess regurgitation
-To doppler b/c we want as parallel to flow as possible
-To mimic apical views b/c maybe those views were suboptimal + could not assess well there
What are we assessing for in the 4CH view?
-Pericardial effusion (right sided collapse)
-VSD
-ASD
-LV size + function
-RV size, function + wall thickness
-RA/LA size
-Intra cardiac masses
-Pacer wires
How do we acquire the IVC/Hep view from 4CH view?
-Rotate counter clockwise to 12 o’clock
-Angle to pt’s right
What structures are seen in the IVC/Hep view?
-Liver
-IVC
-RA
-TV
-HV
Why is the IVC collapsible with inspiration?
-B/c veins don’t have thick walls
-Taking a breath in or sniff decreases intra thoracic pressure causing IVC to collapse
What is the IVC collapsing used to signify?
Used to signify normal central venous pressure
If the IVC fails to collapse more than 50% during inspiration, what does this indicate?
Elevated RA pressure
How do we measure the IVC?
Inner to inner of IVC at largest diameter + again at smallest diameter just distal to IVC/HV junction
Why would a breathe hold not be recommended for visualizing the IVC?
B/c it won’t collapse
List the RA pressure for normal, normal/abnormal + abnormal?
Normal: 3 mmHg
Normal/Abnormal: 8 mmHg
Abnormal: 15 mmHg
List the IVC size, % collapse + RAP when considered low/normal?
Size: < 2.1 cm
Collapse: > 50%
RAP: 3 mmHg
List the IVC size, % collapse + RAP when considered high/abnormal?
Size: > 2.1 cm
Collapse: < 50%
RAP: 15 mmHg
List the IVC size, % collapse + RAP when considered intermediate?
Size: < 2.1 cm (normal) or > 2.1 cm (abnormal)
Collapse: < 50% (abnormal) or > 50% (normal)
RAP: 8 mmHg
How can we optimize our IVC/Hep view?
-Rotate to visualize IVC opening into RA
-Rock to center image
-Angle slightly lateral to visualize HV alongside IVC
What are we assessing for in IVC/Hep view?
-IVC diameter + collapsibility
-HV size
How should we put CD over the IVC/Hep view?
-Either place box over both structures or optimize for each structure separately
-Possibly decrease scale to allow for vessel filling
CD flow should be primarily what color in the IVC/HV?
Blue - b/c venous return flows from IVC/Hep into RA
Why do we sometimes see red flow in IVC/Hep, even in a normal pt?
B/c it is a pulsatile vascular structure, the vein stops/starts to the beat of the heart
How can we obtain the abdominal Ao view from the IVC/Hep view?
Angle towards pt’s left side
What structures are seen in the abdominal Ao view?
-Liver
-Abdominal Ao
How can we optimize for the abdominal Ao view?
-Rock to center image
-Ask pt to breath in + hold it
-Rotate slightly counter clockwise to open up + elongate vessel
How can we differentiate the AO from the IVC?
-Use CD
-Structure of walls
-Location of anatomy (Ao should not connect to right side of heart)
What are we assessing for in the abdominal Ao view?
-Size + structure
-Aneurysms + dissection
-Diastolic flow reversal in presence of Ao regurg
How can we optimize our image when applying CD to the abdominal Ao?
-Angle Ao more vertically to allow for better color visualization
-Place CD box over Ao + make as big as possible, while maintaining FR
-Increase scale
What color should CD flow in the abdominal Ao be?
Red antegrade flow
Are we able to visualize a subcostal short axis?
Yes, similar to PSAX:
-AoV + RVOT
-MV
-PM
-Apex (not always possible)
What can we assess in the SUB short axis views?
Can potentially assess valves, ventricular size, function, wall motion, etc.
If the SUB short axis views are so wonderful, why don’t we always use them?
B/c the parasternal views are usually more optimal since we are closer to the heart
How can we obtain the SSAX AoV view?
-Angle medially (to pt’s left) from IVC/Hep view
-Rotate to open up structures + round out the LV
How can we obtain the SSAX MV + PM levels?
From each level continue to angle leftward through the LV scan plane to shift from AoV level, to MV, to PM, + possibly even apex
How can we optimize our SSAX views?
-Zoom in
-Rock to center
-Get pt to breath in + hold it
-Rotate clockwise or counter clockwise to visualize all structures in each imaging plane
How can we apply CD to our SSAX views?
-Apply all the same options of utilizing color that we would apply to PSAX here
-Breath in helps
(often a helpful window in TDS with pt’s who have lung issues)
How can we obtain the bicaval view from the IVC/Hep view?
-Sweep probe towards pt’s right mid clavicular region, to the right + cephalad/superior
-Increase sector + depth to accommodate for SVC coming into view
What is the bicaval view?
We see the IVC + SVC both coming + draining into the RA
Where should we put our CD box when imaging the bicaval view?
-Place box over IVC, RA + SVC to assess venous return into RA
-Place box over IAS to assess for ASDs again
Color flowing into RA from IVC in bicaval view will be what color?
Blue
Color flowing into RA from SVC in bicaval view will be what color?
Red
How can we obtain the situs view from SUB 4CH?
Angle very posteriorly
(probe will be essentially perpendicular to abdominal wall)
Abnormal situs has a high correlation to what?
Cardiac abnormalities
What is situs solitus?
Normal orientation: liver primarily on pt’s right side with stomach + Ao to the left of spine
What is situs inversus?
Flipped orientation: liver primarily on pt’s left side with stomach + Ao to the right of spine
What is situs ambiguous?
-When position of vessels + liver can not be reliably determined
-High association with congenital cardiac defects
(image shows liver in center with Ao on pt’s right + IVC on pt’s left)
How can applying CD to our situs view help us?
Can help us differentiate b/w which vessel we are seeing:
Ao = red flow
IVC = blue flow
