Optimizing Probe Position and Knobology For Image Acquisition



Optimizing Probe Position and Knobology For Image Acquisition


Lydia Chang





1. Which of the following best describes the tilt motion used to optimize image acquisition?


A. The transducer remains in the same position and angle against the chest wall while the orientation marker is adjusted in a clockwise or counterclockwise motion.


B. The transducer is moved across the chest wall to a new position.


C. The transducer remains in the same position on the chest wall and the same long-axis orientation to the heart while angled to obtain different imaging planes.


D. The transducer remains in the same position on the chest wall and long-axis imaging plane while adjusted toward or away from the orientation marker.

View Answer

1. Correct Answer: C. The transducer remains in the same position on the chest wall and the same longaxis orientation to the heart while angled to obtain different imaging planes.

Rationale: When tilting the probe to optimize acquisition, the transducer remains in the same footprint and long-axis orientation and is moved perpendicular to the axis of the imaging plane to obtain different imaging planes (Answer C) (e-Figure 10.1). When rotating the probe, the transducer remains in the same footprint and angle against the chest, while it is adjusted by rotating clockwise or counterclockwise (Answer A). When rocking the probe to optimize image acquisition, the transducer remains in the same position against the chest wall and long-axis imaging plane, while the agle of the probe is adjusted parallel to the imaging plane, toward or away from the orientation marker (Answer D). Sliding the probe refers to moving the transducer over the patient’s skin to a new position (Answer B).

Selected References

1. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.

2. Zimmerman JM, Coker BJ. The nuts and bolts of performing Focused Cardiovascular Ultrasound (FoCUS). Anesth Analg. 2017 Mar;124(3):753-760. doi: 10.1213/ANE.0000000000001861. PMID: 28207445.



2. Which of the following motions should be used to optimize the parasternal long-axis view shown in Figure 10.1?







A. The transducer should be rocked toward the orientation marker and slightly rotated.


B. The transducer should be tilted to obtain a more anterior imaging plane.


C. The transducer should be rotated clockwise by 90°.


D. The transducer should be angled toward the apex.

View Answer

2. Correct Answer: A. The transducer should be rocked toward the orientation marker and slightly rotated.

Rationale: The ultrasound beam in an optimized parasternal long-axis view should be perpendicular to the left ventricle such that the left ventricle lies horizontal in the view. The plane should bisect the mitral and aortic valves. Figure 10.1 is both off-angle and off-plane. Rocking the probe toward the orientation marker would angle the left ventricle more perpendicularly to the ultrasound beam and slight rotation would get the aortic valve into plane. Tilting the probe more anteriorly would result in the RV outflow view. Rotation by 90° would result in the parasternal short-axis view. Angling toward the apex would further move the LV cavity away from the horizontal position in the view.

Selected References

1. Baston CM, Moore C, Krebs EA, Dean AJ, Panebianco N. Pocket Guide to POCUS: Point of Care Tips for Point of Care Ultrasound. McGraw Hill; 2018.

2. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

3. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.




3. Which motion should be used to acquire the parasternal short-axis from the parasternal long-axis view?


A. The transducer should be angled medially.


B. The transducer should be rotated 90° without any angulation or tilting.


C. The transducer should be tilted anteriorly.


D. The transducer should be rocked away from the orientation marker.

View Answer

3. Correct Answer: B. The transducer should be rotated 90° without any angulation or tilting.

Rationale: To obtain the parasternal short-axis view from the parasternal long-axis view, the transducer should be rotated 90° clockwise without angulation or tilting. This results in good cross-sectional views of the heart.

Selected References

1. Baston CM, Moore C, Krebs EA, Dean AJ, Panebianco N. Pocket Guide to POCUS: Point of Care Tips for Point of Care Ultrasound. McGraw Hill; 2018.

2. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

3. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.



4. Following acquisition and optimization of Figure 10.2, which of the following motions should be performed to acquire the right ventricular (RV) outflow tract view?







A. The transducer should be tilted inferiorly to the right hip.


B. The transducer should be rotated clockwise and tilted anteriorly.


C. The transducer should be tilted superiorly.


D. The transducer should be rocked away from the orientation marker.

View Answer

4. Correct Answer: B. The transducer should be rotated clockwise and tilted anteriorly.

Rationale: To obtain the parasternal RV outflow view from the standard parasternal long-axis view, the transducer should be rotated slightly clockwise and the probe tilted slightly anteriorly toward the base of the heart. This view should allow visualization of the RV outflow tract, two leaflets of the pulmonic valve, and the pulmonary artery. In some instances, the bifurcation of the pulmonary artery can be viewed.

Selected Reference

1. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.



5. What motion is performed in order to obtain Figure 10.3 from the parasternal long-axis view?








A. The transducer is tilted inferiorly to the right hip.


B. The transducer is rotated counterclockwise 90°.


C. The transducer is tilted superiorly.


D. The transducer is rocked away from the orientation maker.

View Answer

5. Correct Answer: A. The transducer is tilted inferiorly to the right hip.

Rationale: The RV inflow view is obtained from the standard parasternal long-axis view by tilting the probe inferiorly to the rip hip. This view displays only the right ventricle, right atrium, and tricuspid valve. The left ventricle should not be visualized. Two leaflets, the anterior and septal (or posterior) leaflets, of the tricuspid valves are displayed.

Selected References

1. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

2. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.



6. Which of the following motions should be performed to move from the view in Figure 10.4A and 10.4B?







A. Tilting


B. Rocking


C. Sliding


D. Angulation

View Answer

6. Correct Answer: A. Tilting

Rationale: The parasternal short-axis view is obtained by rotating 90° clockwise from the parasternal longaxis view. From there, the various levels (or cross sections) of the parasternal short-axis view can be obtained by tilting superiorly and inferiorly. The superior-most view is the level of the great vessels, followed by the level of aortic valve, then the mitral valve, the mid-ventricular tomographic plane, and finally the apex. The mid-ventricular view is particularly important in evaluating global LV function and regional wall motion.

Selected References

1. Baston CM, Moore C, Krebs EA, Dean AJ, Panebianco N. Pocket Guide to POCUS: Point of Care Tips for Point of Care Ultrasound. McGraw Hill; 2018.

2. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

3. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.



7. Figure 10.5 was obtained on a patient erroneously suggesting a hyperdynamic and underfilled left ventricle.






In addition to slight rotation, how would you maneuver the probe to better view the left ventricle in the long axis?


A. Tilt and slightly rotate to capture the left ventricle at its widest dimension.


B. Rock away from the orientation marker on the screen and angle toward the apex.


C. Slide closer to the sternum to better view the ascending aorta.


D. Rotate 90° clockwise.

View Answer

7. Correct Answer: A. Tilt and slightly rotate to capture the left ventricle at its widest dimension.

Rationale: The transducer is off-axis and not positioned to identify the LV cavity in its widest dimension, thus end-systolic effacement of the LV cavity appears to be occurring. As Figure 10.5 already includes the long-axis view of the aortic valve and the mitral valve, tilting and slightly rotating the probe to capture the left ventricle at its widest point would probably be the combination of motions most likely to best capture an optimal long-axis view.

Rocking and angling toward the apex would result in further angulation of the left ventricle away from the ultrasound beam. Sliding the probe toward the sternum would move the probe away from the key region of interest, which is the left ventricle. Rotation of the probe by 90° would result in a view of the parasternal short axis at the level of the aortic valve.

Selected References

1. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

2. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.




8. Figure 10.6 was obtained on a patient, erroneously suggesting that the patient has septal flattening of the left ventricle.






What likely occurred?


A. Over- or underrotation of the transducer


B. Placement of the transducer too close to the sternum


C. Placement of the transducer too far from the sternum


D. Tilting of the transducer too superiorly

View Answer

8. Correct Answer: A. Over- or underrotation of the transducer

Rationale: The transducer is overrotated in the parasternal short-axis view, resulting in a nonperpendicular tomographic plane. This results in a more elliptical appearance of the left ventricle that could be erroneously interpreted as septal flattening.

Selected References

1. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

2. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.



9. A good starting transducer position to obtain the apical four-chamber view is:


A. Inferolaterally to the left nipple with the orientation marker pointed to the 3 or 4 o’clock position


B. Inferolaterally to the left nipple with the orientation marker pointed to the 6 or 7 o’clock position


C. Inferomedially to the left nipple with the orientation marker pointed to the 3 or 4 o’clock position


D. Inferomedially to the left nipple with the orientation marker pointed to the 6 or 7 o’clock position

View Answer

9. Correct Answer: A. Inferolaterally to the left nipple with the orientation marker pointed to the 3 or 4 o’clock position

Rationale: The transducer is best positioned at the anatomic apex of the left ventricle with the patient placed in the left lateral decubitus position. The septum should be oriented vertically along the center of the screen and the tomographic plane adjusted so that it bisects the apex and the midpoint of the tricuspid and mitral orifices.

Selected References

1. Levitov AB, Mayo PH, Slonim AD. Critical Care Ultrasonography. McGraw Hill; 2014.

2. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for performing a comprehensive transthoracic echocardiographic in adults: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;32(1):1-64.

Jun 9, 2022 | Posted by in CARDIOLOGY | Comments Off on Optimizing Probe Position and Knobology For Image Acquisition
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