Authentic ARDMS Certification Exam AE-Adult-Echocardiography Questions Answers

The echocardiographic image/video shows decreased brightness and penetration in the near field, making the anterior cardiac structures poorly visualized while deeper structures appear brighter. This indicates under-gain in the near field.

Increasing the time gain compensation (TGC) in the near field enhances the signal strength of superficial structures without affecting deeper tissues. This adjustment improves image quality by balancing the brightness across the field.

Increasing compression or decreasing overall gain would reduce the signal globally and are not specific for near field optimization. Decreasing TGC in the far field would reduce brightness deeper but does not address near-field issues.

This principle is outlined in the "Textbook of Clinical Echocardiography, 6e", Chapter on Image Optimization and Technical Settings【20:70-75†Textbook of Clinical Echocardiography】.

Comprehensive and Detailed Explanation From Exact Extract:

The Qp/Qs ratio represents the ratio of pulmonary blood flow (Qp) to systemic blood flow (Qs). It is commonly calculated to quantify the magnitude of a left-to-right shunt in congenital heart disease.

To calculate Qp/Qs using echocardiography, stroke volumes across both the pulmonary and systemic outflow tracts are measured by combining the cross-sectional area of the outflow tract and the velocity time integral (VTI) of flow through it.

Pulmonary blood flow (Qp) is calculated using the right ventricular outflow tract (RVOT) diameter and RVOT VTI. Systemic blood flow (Qs) is calculated using the left ventricular outflow tract (LVOT) diameter and aortic valve VTI.

Thus, RVOT VTI is essential for Qp calculation, making option D correct.

This method is explained in detail in the "Textbook of Clinical Echocardiography, 6e", Chapter on Congenital Shunts and Quantification of Flow【20:360-365†Textbook of Clinical Echocardiography】.

The continuity equation calculates aortic valve area (AVA) by equating stroke volume through the left ventricular outflow tract (LVOT) to stroke volume through the aortic valve. The equation is:

AVA = (Cross-sectional area of LVOT) × (LVOT VTI) / (Aortic valve VTI)

The cross-sectional area of the LVOT is derived from the LVOT diameter, using the formula π × (diameter/2)^2. Because the diameter is squared in this calculation, even a small error in measurement leads to a significant error in the calculated valve area.

This makes the LVOT diameter measurement the greatest source of error when calculating AVA by the continuity equation. Errors in Doppler velocity measurements (LVOT velocity or aortic jet velocity) are also important but less impactful compared to diameter measurement error.

Aortic valve planimetry is a direct measurement method, not part of the continuity equation. LVOT velocity recorded with pulsed Doppler and aortic jet velocity by continuous wave Doppler are important but not the greatest error source.

This is a well-established concept described in the "Textbook of Clinical Echocardiography, 6e", Chapter on Valvular Stenosis and Continuity Equation Methodology【20:370-375†Textbook of Clinical Echocardiography】.