ClinCorr 7- Echocardiography

Question 1

The heart is routinely imaged from which three standard windows?

Answer 1

parasternal, apical, and subcostal (and suprasternal)- these are all cardiac window

Question 2

For a parasternal view, where should the phased-array transducer be placed?

Answer 2

immediately to the left of the sternum in the 3rd or 4th intercostal space

marker should be facing the patient’s right shoulder

Question 3

What are cardiac window?

Answer 3

windows on the anterior chest wall through which an ultrasound beam can effectively reach the heart without being blocked

Question 4

Is there any prep for a echocardiography? Does the patient need to fast?

Answer 4

No

Question 5

What is the ideal patient position for an ECG using the parasternal or apical window?

Answer 5

left lateral decuibdeous (can be done supine)

Question 6

What should be the frequency range of a cardiac probe?

Answer 6

1.5-3.6 MHz

Question 7

During PLAX cardiac imaging, should the orientation marker be to the right or the left of the image?

Answer 7

Right. For all other cardiac (and all other ultrasound) images, it will be to the left by default.

Many years ago, echocardiographers adopted the convention of having the screen indicator oriented to the left side of the image. This is opposite to the convention used with ultrasounds of other organs, where the screen indicator is positioned to the right. This means that in all cardiac ultrasounds, the transducer indicator should be directed to the patient’s left side, with the exception of the PLAX view (where it is directed toward the patient’s right shoulder).

Question 8

What are the ideal ‘depths’ for a) parasternal and b) subcostal or apical views

Answer 8

a) shallower 12-16 cm

b) deeper 16-22 cm

Question 9

What is the best window to begin looking at the heart?

Answer 9

parasternal

Question 10

Where does the long axis of the heart run?

Answer 10

base of the heart near the right atrium (superior) to the apex of the heart

the probe marker should be oriented toward the patient’s right shoulder

Question 11

How do you perform a parasternal short-axis ECG?

Answer 11

The key to obtaining good short-axis views is to start with a high-quality parasternal long-axis image. First, center the transducer over the mitral valve in the PLAX view. Then, rotate the transducer 90 degrees, so that the indicator points toward the patient’s left shoulder. Be careful not to allow the transducer to slide on the chest as you do so. Fixing your hand on the patient while rotating the probe between your fingers (without rotating your wrist) will help keep the transducer in position. Be sure that the image of the LV cavity is circular, indicating a true cross-section. If the LV cavity appears oval, the beam is off-axis and interpretations of LV function and wall abnormalities will be erroneous. The other short-axis views are obtained by tilting the position of the transducer alternately toward the right shoulder and then progressively back toward the left hip from the same position on the chest

Question 12

What are the four positions for obtaining a short axis parasternal view?

Answer 12

aortic valve, mitral valve, mid-ventricle, apex

Question 13

What things will you see in a parasternal short axis aortic view?

Answer 13

LA, RA, RV, aortic valve, tricuspid valve

Question 14

What things will you see in a parasternal short axis mitral view?

Answer 14

RV, mitral valve

Question 15

What things will you see in a parasternal short axis mid-ventricle view?

Answer 15

RV, LV, papillary muscles, interventricular septum

Question 16

What things will you see in a parasternal short axis apex view?

Answer 16

RV and LV

Question 17

What things will you see in a parasternal long axis view?

Answer 17

LV, LA, aortic outflow tract, RV, AV valve, mitral valve, interventricular septum, posterior wall of the LV, and the pericardium

make sure to set the depth so the pericardium and the posterior wall of the LV are included

Question 18

What is the difference between tilting and angling probes?

Answer 18

tilting- if you’re looking at a probe that has the wide part to the right and the left, tilting would be moving the probe forward like the beginning of a person falling forward

angling- if you’re looking at a probe that has the wide part to the right and the left, angling would be moving the left or the right side up

Question 19

What could help optimize an image?

Answer 19

having the patient exhale deeply

Question 20

In a parasternal long-axis view (and just in general), how much should the thickness of the LV increase during systole?

Answer 20

50% increase (and should contract toward the center of the cavity)

Question 21

What is resolution?

Answer 21

the ability to distinguish nearby structures on an image

Image resolution is divided into axial, lateral, elevational and temporal components

Question 22

What is axial resolution determined by?

Answer 22

primarily by the sound wave frequency. Higher frequencies enhance axial resolution, but cannot penetrate as deeply in the body.

Question 23

What is elevational resolution determined by?

Answer 23

determined by the transducer’s width. Temporal resolution applies to moving structures.

Question 24

lateral resolution

Answer 24

Lateral (i.e., horizontal resolution) is maximal when the object of interest is positioned within the transducer’s focal zone, which is the narrowest portion of the beam. Lateral resolution decreases as deeper structures are imaged due to divergence and increased scattering of the beam. To improve lateral resolution when imaging deeper structures, the depth of the focal zone should be increased to the level of the target structure.