Tools of the Trade Flashcards
What are the two standard CXR views?
PA (posterior-anterior) and Lateral
Why is Posterior-Anterior good for viewing the heart in CXR?
In posterior-anterior XR, the radiation is shot through the back and hits the film in front of the patient. Because, the heart sits more anterior in the chest cavity, there is less distance between the film and the heart in posterior-anterior than if the XR was shot anterior-posterior.
For lateral XR, which side is the film on when imaging the heart?
The film would be on the left side of the patient. You always want to have the film close to the object you’re trying to image it’s most accurate. Since the heart is on the left, the film will be on the left. The XR will be shot from right side of the patient.
Why is bone white and air black in XR?
In XR, radiation is shot at a film and the radiation is blocked by dense things. So, things like metal and bone are very dense so they block the radiation and show up as white on the film. Air is least dense and show up black
Does Echocardiogram use radiation?
No
How does Echocardiogram get its image?
It shoots ultrasound into the body, strikes objects, and returns to the transducer too form image.
What are the 4 functions/modes of Echocardiogram?
- 2-dimensional motion picture
- M-Mode
- Color Doppler map of blood flow
- Spectral Doppler map of blood or tissue velocity
Which ventricle is more anterior?
Right ventricle
Where is the esophagus in relation to the heart?
The esophagus goes behind the heart, specifically behind the left atrium.
What color is fluid in ultrasound?
Black
What is a trans-esophageal echocardiogram?
This is when you have a patient swallow the probe and you can image the heart through the esophagus.
What is an added benefit to doing the trans-esophageal echocardiogram?
Since you can get closer to the heart with the probe, you can use a higher-resolution probe to image.
What is the M-Mode echocardiogram?
This is when your probe actually shoots down in straw-like sections. (imagine if you took a straw and poked through the layers).
What is the X axis on M-Mode echocardiogram?
Time
What is the Y axis on M-Mode echocardiogram?
Movement
What was the earliest form of echocardiogram?
M-Mode
What is M-Mode good at?
M-Mode is great at observing physical dimensions or change in time. Since the M-Mode was the first echocardiogram version, many standard measurements of the heart are understood through M-Mode. It’s also great at making measurements and differences in timing comparing between structures.
For ultrasound color doppler, what colors represents towards the transducer and what colors represent away from the transducer?
Red/yellow = towards transducer, Blue/white = away from transducer
What is the diameter of a RBC?
6-8 microns
How small does something have to be to get through the pulmonary capillaries?
Less than 10 microns
How can you use agitated saline to detect shunts?
Agitated saline created micro-bubbles around 16 microns in diameter. Since these are more than 10 microns, they won’t make it through the capillaries of the pulmonary system. So, you inject agitated saline into the venous system, and you should be able to see it on the right side of the heart but not the left. If you see micro bubbles in the left side of the heart, that means that there is either an intra-cardiac shunt or intra-pulmonary shunt.
How can you tell the difference between a patent foramen ovale v.s. an atrial septal defect? (when using agitated saline)
A patent foramen ovale should have blood flowing from right atrium to left atrium because the flap only opens one way. The flap is typically held closed because the left side of the heart has higher pressure… the flap would only be open during times that the right atrium has higher pressure than left atrium.
In atrial septal defect, you have bidirectional shunt. The blood would flow from left atrium to right atrium because the left side of the heart has higher pressure. When viewing the ultrasound with agitated saline, you can see that there are black puffs coming from the left atrium into the right. These are black because the blood coming from the left atrium doesn’t have any bubbles.
What are 11 things that can be obtained from Echocardiography?
- Chamber size
- Function
- Chamber structure
- Wall motion
- Valves
- Pressure and hemodynamics
- Shunts
- Murmurs
- Intracardiac masses
- Bacterial endocarditis
- Pericardial disease
What is the purpose of a stress test?
Stress test is supposed to increase myocardial oxygen demand so that you can identify potential ischemia.