Echocardiography Board Review: 500 Multiple Choice Questions With Discussion

Chapter 5

Questions

1.  81. The Doppler signal is consistent with:c05g001

1.  A. Severe aortic regurgitation and moderate aortic stenosis

2.  B. Severe mitral stenosis

3.  C. Acute severe mitral regurgitation

4.  D. Ventricular septal defect

2.  82. Pulse duration is affected by:

1.  A. Source of ultrasound

2.  B. B.Transmission medium

3.  C. Both

4.  D. Neither

3.  83. The pulse repetition frequency (PRF) is affected by:

1.  A. Source of ultrasound

2.  B. Transmission medium

3.  C. Both

4.  D. Neither

4.  84. What happens to the PRF when imaging depth is increased?

1.  A. Increases

2.  B. Decreases

3.  C. C.Does not change

4.  D. Effect is variable

5.  85. By increasing the PRF, the axial resolution:

1.  A. A.Increases

2.  B. Decreases

3.  C. Does not change

6.  86. Imaging at depth affects:

1.  A. Axial resolution

2.  B. Lateral resolution

3.  C. Neither

4.  D. Both

7.  87. Reducing the transducer footprint will affect:

1.  A. Lateral resolution

2.  B. Temporal resolution

3.  C. Axial resolution

4.  D. None of the above

8.  88. Increasing the transmit power will:

1.  A. Decrease sensitivity

2.  B. Increase lateral resolution

3.  C. Increase penetration

4.  D. None of the above

9.  89. Acoustic impedance equals (rayls):

1.  A. Density in kg/m3 × speed of sound in m/s

2.  B. Density in kg/m3 × transducer frequency in MHz

3.  C. Depth in meters × transducer frequency in MHz

4.  D. None of the above

10. 90. Reflection of sound at an interface is affected by:

1.  A. Specific acoustic impedance

2.  B. Transducer frequency

3.  C. Depth

4.  D. None of the above

11. 91. The most common cause of coronary sinus dilatation is:

1.  A. Heart failure

2.  B. Persistent left superior vena cava

3.  C. Atrial septal defect

4.  D. None of the above

12. 92. The following data were obtained from a 72-year-old man with a calcified aortic valve: left ventricular outflow tract (LVOT) velocity (V1) 0.8 m/s, transaortic velocity (V2) 4 m/s, LVOT diameter 2 cm.The calculated aortic valve area (AVA) is:

1.  A. 0.4 cm2

2.  B. 0.6 cm2

3.  C. 0.8 cm2

4.  D. 1 cm2

13. 93. The continuity equation is an example of:

1.  A. Law of conservation of mass

2.  B. Law of conservation of energy

3.  C. Law of conservation of momentum

4.  D. None of the above

14. 94. The most practical value for the development of perfluorocarbon bubbles was to improve:

1.  A. Contrast on the right side

2.  B. Stable passage through the transpulmonary bed to improve contrast on the left side

3.  C. Improve contrast visualization in the hepatic bed

4.  D. None of the above

15. 95. In a patient with mixed aortic valve disease, the AVA by the Gorlin equation using Fick cardiac output is likely to be:

1.  A. Less than by the continuity equation

2.  B. More than by the continuity equation

3.  C. The same by both methods

16. 96. In a patient with mixed aortic valve disease, the AVA by the Gorlin equation using angiographic cardiac output is likely to be:

1.  A. Less than by the continuity equation

2.  B. More than by the continuity equation

3.  C. The same by both methods

17. 97. The following measurements were obtained from a mitral regurgitant jet: radius of proximal isovelocity surface area = 1 cm, aliasing velocity = 40 cm/s. The peak regurgitant flow rate equals:

1.  A. 251 cc/s

2.  B. 251 cc/min

3.  C. 125 cc/min

4.  D. 125 cc/s

18. 98. In the patient above, the systemic blood pressure is 120/80 mmHg in the absence of aortic stenosis and the left atrial pressure is 20 mmHg. The effective mitral regurgitant orifice area would be:

1.  A. 0.7 cm2

2.  B. 0.5 cm2

3.  C. 1 cm2

4.  D. Cannot be calculated

19. 99. This effective regurgitant orifice (ERO) area of 0.5 cm2 represents:

1.  A. Mild mitral regurgitation (MR)

2.  B. Moderate MR

3.  C. Severe MR

4.  D. Severity cannot be detected

20. 100. If the patient in question 99 had a blood pressure of 220/90 mmHg with similar proximal isovelocity surface area (PISA) measurements, the ERO area would:

1.  A. Remain unchanged

2.  B. Be more

3.  C. Be less

Answers for chapter 5

1.  81. Answer: C.

Acute severe mitral regurgitation (MR). The image shows the classical “V wave cut-off” sign. The rapid deceleration of the MR velocity profile following the peak velocity is due to a rapidly diminishing left ventricular to left atrial (LV–LA) pressure gradient secondary to a large V wave in the left atrium that is a feature of severe MR, especially when it occurs acutely.

2.  82. Answer: A.

Source of ultrasound. Speed of ultrasound transmission does not affect pulse duration but affects wavelength. Pulse duration is determined by the transducer setting.

3.  83. Answer: A.

PRF is also a function of source of ultrasound and is not affected by medium of transmission. Speed of ultrasound transmission affects only lengths not the durations or frequency.

4.  84. Answer: B.

It decreases because of an increase in time of flight. PRF = 77 000/depth in cm.

5.  85. Answer: C.

The PRF does not affect axial resolution. Axial resolution is determined by spatial pulse length, which is mainly determined by wavelength (i.e., ultrasound frequency) and number of cycles in the pulse as transmission speed in biological systems is fairly fixed.

6.  86. Answer: B.

Lateral resolution drops because of beam divergence and widening. Axial resolution is unaffected by depth but is affected by wavelength (in frequency) and number of cycles in a pulse, which together make up spatial pulse length.

7.  87. Answer: A.

It will affect beam width and hence the lateral resolution.

8.  88. Answer: C.

Penetration increases due to more power. The sensitivity increases but lateral resolution decreases due to increasing beam width.

9.  89. Answer: A.

Acoustic impedance in rayls = density (kg/m3) × speed of ultrasound (m/s). Average soft tissue impedance is 1 630 000 rayls.

10. 90. Answer: A.

11. 91. Answer: A.

Heart failure is the common cause of dilatation of the coronary sinus. Although persistent left superior vena cava (SVC) causes dilatation of the coronary sinus, it occurs infrequently. In the absence of heart failure, persistent left SVC is the most common cause of enlarged coronary sinus. Dilatation can occur either due to increased flow in the coronary sinus or due to increased right atrial pressure. The other causes include coronary arteriovenous fistula and unroofing of the coronary sinus. Unroofed coronary sinus results in a left to right shunt, a variant of atrial septal defect.

12. 92. Answer: B.

The valve area can be calculated with the continuity equation.

A1V1 (LVOT area × LVOT velocity) = A2V2 (aortic valve area × aortic velocity). A2 = A1V1/V2A1 = πr2 (r = LVOT diameter/2) = 3.14 × 1 × 1 = 3.14 cm2A2 = 3.14 × 0.8/4 = 0.6 cm2.

13. 93. Answer: A.

States that mass cannot be destroyed and hence flow rates at different locations in a flow stream are the same at a given point in time.

14. 94. Answer: B.

The development of perflorocarbon bubbles increased stable passage through the pulmonary bed, so that contrast visualization was better on the left side.

15. 95. Answer: A.

The cardiac output by the Fick method is less than the transaortic flow, which is Fick cardiac output + regurgitant volume. Hence the calculation of AVA by Gorlin will underestimate AVA compared to AVA by the continuity equation. Gorlin equation will overestimate aortic stenosis severity.

16. 96. Answer: C.

Angiographic and Doppler cardiac output would be equal.

17. 97. Answer: A.

The regurgitant flow rate is calculated by the formula 2πr2 × aliasing velocity. This formula assumes a hemispherical geometry. Hence it is vital to optimize the aliasing velocity to maximize the hemisphere of the PISA in all dimensions. Using the formula, peak flow rate = 2πr2 = 2 × 3.14 × 1 × 1 × 40 = 251.2 cc/s.

18. 98. Answer: B.

The LA–LV pressure gradient is 100 mmHg, which corresponds to a peak mitral regurgitant velocity of 5 m/s or 500 cm/s. The ERO area is given by the formula 2πr2 × aliasing velocity (peak flow rate)/MR velocity. In this patient, peak flow rate = 251 cc/s and ERO is 251/500 = 0.5 cm2.

19. 99. Answer: C.

This patient has severe MR. The ERO is a fairly stable measure of quantitating MR as it represents the defect in the mitral valve co-aptation mechanism and is independent of loading conditions. ERO < 0.2 is mild, 0.2–0.4 is moderate, and ≥0.4 cm2 is severe MR.

20. 100. Answer: C.

Since the blood pressure is now elevated, the LV–LA pressure gradient is 200 mmHg, giving rise to an MR jet of 7 m/s. The ERO now is 251/700 = 0.3 cm2. If the ERO were unchanged, the peak flow rate would be increased because of higher driving pressure and the PISA radius would be increased.