Three-Dimensional Echocardiography
Ben A. Lin
Lissa Sugeng
1. Early efforts in three-dimensional (3D) imaging required a series of two-dimensional (2D) images. Which method(s) use this approach?
A. Sparse matrix array.
B. Fully sampled matrix array.
C. Freehand and mechanically driven scanning.
D. Phased array.
E. Pyramidal array.
View Answer
1. Answer: C. Three-dimensional echocardiography (3DE) has evolved over several decades since the 1970s. Initial 3DE methods of acquiring a 3D volume required multiple 2D images obtained with either freehand scanning or a mechanically driven transducer and typically gated to the ECG. Freehand scanning is achieved by collecting a series of 2D images along a fixed plane. A spatial locator coupled with a commercially available transducer determines the 3D location onto a Cartesian coordinate system. These locators can be either a spark gap system or an electromagnetic field. A mechanically driven transducer obtains multiple images at a fixed window and set intervals in a parallel, rotational, or fanlike manner. These images are then converted into a Cartesian coordinate system for further analysis.
2. Which factors affect the quality of 3D reconstructions derived from 2D images?
A. 2D image quality, motion artifact, and electrocardiogram (ECG) and respiratory gating.
B. 2D image quality.
C. Image density.
D. ECG and respiratory gating.
E. Image density, gain, persistence, and frame rate.
View Answer
2. Answer: A. The quality of a 3D reconstruction using multiple 2D images depends on the quality of the 2D images and the ability to avoid motion during acquisition by either the operator or the patient. ECG and respiratory gating were also essential in ensuring the location in time and space. Hence, patients with atrial fibrillation or irregular heartbeats were usually excluded in studies. The data integrity in such patients could not be ensured.
3. The current generation of fully sampled matrix array transducers typically contains:
A. 50 piezoelectric elements.
B. 1,000 piezoelectric elements.
C. 3,000 piezoelectric elements.
D. 10,000 piezoelectric elements.
E. 30,000 piezoelectric elements.
View Answer
3. Answer: C. The development of fully sampled matrix array transducers was introduced in 2003. These utilize at least 3,000 piezoelectric elements that are connected to miniaturized circuit boards with improved crystal technology for better-image quality. Most, but not all, 3D transducers are able to perform 2D, color Doppler, pulse, and continuous wave Doppler as well as 3D/4D imaging. Although smaller in size, the footprints of these probes are still slightly larger than that of a traditional 2D probe.
4. To achieve a higher volume rate (volumes per second or vps), the operator should make the following adjustment on the ultrasound system:
A. Choose a multibeat acquisition.
B. Decrease the sector size.
C. Increase magnification.
D. All of the above.
E. A and B.
View Answer
4. Answer: E. A multibeat acquisition enables the user to achieve better temporal resolution compared with a single beat acquisition, while maintaining high spatial resolution. In addition, decreasing the imaging depth, decreasing sector width (elevation and lateral), and using a zoom mode of imaging will also increase the volume rate. Magnification does not change spatial or temporal resolution.
5. Which of the following is a cause of stitch artifact?
A. Adjusting gain.
B. Normal sinus rhythm.
C. Normal respiration.
D. Narrowing the sector angle.
E. Zoom imaging.
View Answer
5. Answer: C. Stitch artifact (Fig. 5-15) occurs during a multibeat acquisition where several subvolumes are sequentially obtained over two to seven cardiac cycles. Operator or patient movement, respiratory motion, arrhythmias, or even esophageal motility can cause misalignment of these subvolumes.
 Figure 5-15. Stitch artifact (shown by the red arrows), which is a malignment of adjacent volumes during acquisition. |
6. Which of the following statements is true regarding the accuracy and reproducibility of 2D echocardiography (2DE) versus 3D echocardiography (3DE) in regard to assessment of left ventricular (LV) volumes?
A. 3DE has superior accuracy and reproducibility compared with 2DE.
B. 2DE has better accuracy and reproducibility compared with 3DE.
C. Both 2DE and 3DE have similar accuracy and reproducibility.
D. Both 2DE and 3DE have similar accuracy but differ in reproducibility.
E. All of the above are incorrect.
View Answer
6. Answer: A. Three-dimensional echocardiography has repeatedly been shown to be superior to 2DE when compared with cardiac magnetic resonance imaging (MRI) as a gold standard. Specifically, realtime 3DE studies have demonstrated less variability in repeated measurements (intra- and interobserver variability), which is explained by the ease of obtaining a common long axis in 3D volume data. Image alignment is pivotal in the accuracy of 2D quantitation of LV volumes. Although both 2DE and 3DE underestimate LV volumes, underestimation occurs mostly when using 2DE methods for quantitation (biplane Simpson’s method or method of discs).
7. While 3DE-derived left ventricular (LV) volumes and ejection fraction have good correlation with cardiac magnetic resonance imaging (MRI), there is consistent underestimation of ventricular volumes. To overcome this bias, the operator should:
A. Acquire 3D LV volumes using decreased depth, narrow sector sizes, and single beat acquisitions.
B. Acquire 3D LV volumes using increased depth, narrow sector sizes, and multibeat acquisitions.
C. Acquire 3D LV volumes using single beat acquisitions with increased depth.
D. Acquire 3D LV volumes using decreased depth and multibeat acquisitions for higher temporal resolution.
E. Acquire 3D LV volumes using a sweep method and timed acquisitions.
View Answer
7. Answer: B. The best option here is to acquire using increased depth, narrow sector sizes, and multibeat acquisitions in order to optimize the balance between spatial and temporal resolution. Although there are many reasons for systematic underestimation of volumes, the major issue is achieving adequate image quality to differentiate the LV cavity and trabeculations from compacted myocardium. Recently developed software for LV quantification is based on speckle tracking and/or algorithms that learn to search for compacted myocardium based on images from a library of normal and abnormal subjects. Reproducibility is better using 3DE when compared with 2DE, but this has mostly been based on small studies.
8. Left atrial volume reflects the long-term effects of high left atrial pressure and severity of diastolic dysfunction and is a predictor of mortality and outcome. Which quantitative method has the best test-retest variability?
A. M-mode echocardiography.
B. Prolate ellipsoid.
C. Biplane Simpson’s.
D. Area-length method.
E. 3DE.
View Answer
8. Answer: E. Three-dimensional echocardiography has the lowest test-retest variability compared with other methods, making it the best modality to use for serial follow-up of patients for a long-term.
9. Which statement pertaining to 3D assessment of the right ventricle (RV) is correct?
A. Quantitation of RV function by 3DE is an online program using method of discs.
B. Quantitation of RV volumes is accurate and reproducible using method of discs.
C. Quantitation of RV volumes is a widespread application since it is accurate and reproducible.
D. Quantitation of RV volumes involves geometric modeling and mathematical equations easily performed off-line.
E. Quantitation of RV volumes is similar to LV assessment using a bullet-shaped geometric model.
View Answer
9. Answer: B. The RV has been described as a crescent-shaped ventricle not easily conforming to any geometric shape. Therefore, its quantitative assessment is very difficult. Right ventricle imaging has previously required a reconstructive 3D method using either rotation or a freehand approach, but currently real-time 3DE is the method of choice. Most efforts in quantitation of the RV have utilized the method of discs. This method results in accurate and reproducible assessment. Off-line assessment using a rotational approach and automated border detection has also been proven to be accurate but does not have widespread use.
10. Display of 3D color Doppler data should be performed using the following approach:
A. At least two different views should be used to understand the orientation of the jets.
B. Only one view should be used to determine the severity of a regurgitant jet.
C. Cropping of a 3D color Doppler data set should be performed only at the vena contracta.
D. All of the above.
E. None of the above.
View Answer
10. Answer: A. Three-dimensional color Doppler data are best displayed in two long-axis views (Fig. 5-16) along the narrowest and widest portion of the jet using multiplanar cut planes. It can also be displayed using a volume-rendered image in addition to the multiplanar views.
 Figure 5-16. A volume rendered 3D color-flow Doppler of a mitral regurgitant jet is shown in Panel A. Using 3 MPR views (B-D), the vena contract of the jet (yellow arrows) is seen in three orthogonal long-axis views (B and D) and a short-axis plane at the level of the vena contracta (C). (continued) |
 Figure 5-16. (Continued) |
Figure 5-17 shows, in Panel A, a view of the mitral valve from left atrial orientation. The mitral regurgitant jets are seen en face as it moves into the left atrium. The dotted yellow line is the cut plane that allows visualization of the jet from a long-axis perspective as seen in Panel B.
 Figure 5-17A |
 Figure 5-17B |
11. Three-dimensional color Doppler imaging with current technology is best described as having:
A. High temporal resolution but low spatial resolution.
B. Low temporal resolution but high spatial resolution.
C. Low temporal resolution and low spatial resolution.
D. High temporal resolution and high spatial resolution.
E. None of the above.
View Answer
11. Answer: C. Although we are able to perform 3D color Doppler imaging, the current limitations of this technology are low temporal and spatial resolution. Better temporal resolution can be obtained using multibeat acquisitions over seven cardiac cycles, but this creates a high risk of stitch artifacts. Using a smaller sector size can also aid in increasing temporal resolution, but this decreases the available spatial and anatomic information.
12. Why is the diagnosis of mitral valve prolapse established only in the long-axis view?
A. Based on 2DE studies, the long-axis view is most sensitive in visualizing prolapse.
B. Based on 2DE studies, the 4-chamber and 2-chamber views are less sensitive but more specific in visualizing prolapse.
C. Based on 3DE studies, since the mitral valve annulus is planar, the mitral leaflets ascend above the annulus the most in a long-axis view.
D. Based on 3DE studies, since the mitral valve annulus is nonplanar, the mitral leaflets can ascend above the annulus in a 4-chamber view.
E. The mitral valve annulus, leaflets, and papillary muscles are best seen from a long-axis view.
View Answer
12. Answer: D. The true structure of the mitral valve annulus was revealed in large part on the basis of 3D studies. With this in-depth analysis of the mitral valve, we now understand that the anterior and posterior mitral valve annular points are higher than the medial and lateral mitral annulus. Hence, leaflets in the 4-chamber view appear to rise above the mitral annulus even in the absence of prolapse. This seminal study changed the diagnosis of mitral valve prolapse.
13. Which modality is most accurate and reliable to use for measuring the mitral valve orifice area after balloon mitral valvuloplasty for mitral stenosis?
A. Pressure half-time.
B. Flow convergence method.
C. 2D planimetry.
D. 3D planimetry.
E. Continuity equation.
View Answer
13. Answer: D. In patients post-balloon mitral valvuloplasty, 3DE measurements of the mitral valve orifice are more accurate and reliable compared with the pressure half-time method and 2D planimetry. The continuity equation should not be used in the setting of coexisting aortic or mitral regurgitation, as the latter is usually a complication of valvuloplasty.
14. The mitral valve is correctly displayed from the “surgeon’s view” in which panel? See Figure 5-1:
A. Panel A.
B. Panel B.
C. Panel C.
D. Panel D.
E. None of the above.
 Figure 5-1A |
 Figure 5-1B |
 Figure 5-1C |
 Figure 5-1D |
View Answer
14. Answer: A. The standard display orientation of the mitral valve is shown with labels in Figure 5-18. The aortic valve is usually rotated to the 11-12 o’clock position and the left atrial appendage is at approximately 9 o’clock. The posterior mitral valve leaflet is centered at 6 o’clock (specifically the P2 scallop) and the interatrial septum is between 2 and 3 o’clock. This display is described as the “surgeon’s view,” which is the orientation of the mitral valve when visualized from the left atrium by a surgeon standing on the patient’s right side.
 Figure 5-18. “Surgeon’s view” of the mitral valve from a left atrial orientation. |
15. A 34-year-old man presents with shortness of breath and lower extremity edema. He has had fevers, rigors, and poor appetite for several weeks. He has methicillin-sensitive Staphylococcus aureus bacteremia and a history of drug abuse. On examination, he has poor dentition and he has a holosystolic murmur at the apex directed laterally. Transesophageal 2D echocardiogram (Fig. 5-2, Panels A and B) shows the mitral valve in a 90-degree angle. Panel C is a transesophageal 3D left atrial orientation of the mitral valve. Based on this finding, you conclude that:
A. There is a posterior leaflet (P1) vegetation with mitral regurgitation.
B. There is an anterior leaflet (A1) vegetation and perforation with significant mitral regurgitation.
C. There is a posterior leaflet (P1) vegetation and perforation with significant mitral regurgitation.
D. There is a ruptured chordae with mitral regurgitation.
E. There is a flail mitral leaflet with significant regurgitation.
 Figure 5-2A |
 Figure 5-2B |
 Figure 5-2C |
View Answer
15. Answer: B. This patient has an A1 scallop vegetation and perforation with significant mitral regurgitation. At 90 degrees on a 2D transesophageal echocardiogram, the leaflet scallops coapting in this view are P3 and A3. There is an echodensity on the anterior leaflet adjacent to the left atrial appendage, which is usually the A1 scallop. When color-flow Doppler is applied, the jet penetrates through the leaflet. From a left atrial perspective, this vegetation and perforation can be visualized easily on 3D echocardiography.
See Figure 5-19. Two-dimensional transesophageal echocardiography (Panels A and B) demonstrates a vegetation (red arrow) at the A1 scallop in 90 degrees with mitral regurgitation going through the A1 scallop indicative of a perforation. On 3D transesophageal echocardiography, there is a vegetation (red arrow) with a visible hole through the A1 scallop seen from a left atrial orientation.
 Figure 5-19A |
 Figure 5-19B |
 Figure 5-19C |
 Figure 5-20. Multiplanar reconstruction (MPR) of a zoom-mode acquisition in this patient with mitral stenosis. On the short-axis cross section of the mitral valve, a mitral valve area planimetry was obtained. |
16. What would you do next?
A. Continue with medical management and follow-up with serial echocardiograms.
B. Continue antibiotic therapy and follow-up with serial transesophageal echocardiograms.
C. Ask your interventionalist to close this percutaneously.
D. Ask for a surgical consultation for mitral valve repair.
E. Discharge to drug rehabilitation, continue medical therapy, and arrange for follow-up in clinic.
View Answer
16. Answer: D. The class I indications for mitral valve surgery in the setting of endocarditis include severe mitral regurgitation resulting in heart failure, mitral regurgitation with evidence of elevated LV end-diastolic or left atrial pressure, or moderate/severe pulmonary hypertension, fungal or highly resistant organisms causing endocarditis, or those complicated by heart block, abscess, or destructive lesions (e.g., sinus of Valsalva to right atrium, RV or left atrium fistula; mitral leaflet perforation; or infection in the annulus fibrosa). Severe mitral regurgitation with heart failure and a perforated leaflet were indications for surgery in this patient. Three-dimensional echocardiographic findings were confirmed with intraoperative surgical pathology.
17. A 35-year-old woman from Guatemala has a history of rheumatic fever as a child and balloon valvuloplasty when she was a teenager. She has not had follow-up since her arrival to the United States. She does not complain of shortness of breath with housework. Her echocardiogram shows the following (Fig. 5-3):
A. Mitral valve prolapse and significant mitral regurgitation.
B. Normal opening of the mitral valve consistent with successful balloon valvuloplasty.
C. Decreased opening of the mitral valve leaflets due to low flow.
D. Decreased mitral valve opening due to restenosis.
E. Severe mitral stenosis with atrial fibrillation.
 Figure 5-3A |
 Figure 5-3B |
 Figure 5-3C |
View Answer
17. Answer: D. This patient has moderate mitral stenosis with a moderate transmitral gradient. Figure 5-3 is a view of the mitral valve from an LV perspective. There is doming of the anterior mitral leaflet with medial and lateral commissural fusion. Using multiplanar reconstruction, a 2D cut-plane can be placed at the tips of the mitral leaflet en face to the valve opening to derive a mitral valve area as shown in Figure 5-20. In this case, the mitral valve orifice area was 1.4 cm2.
18. The mitral valve orifice area measured by 3D planimetry demonstrated a mitral valve area of 1.4 cm2 with a mean mitral valve gradient of 5 mm Hg. The right ventricular systolic pressure was 40 mm Hg. Since she does not complain of dyspnea with housework but typically tries not to exert herself, what is your next choice of management?
A. Start amiodarone since she probably has atrial fibrillation as a cause of shortness of breath.
B. Place her on warfarin (Coumadin) since she probably has atrial fibrillation.
C. Inform her that she needs another balloon mitral valvuloplasty.
D. Inform her that she will need a mitral valve repair.
E. Schedule a stress echocardiogram to demonstrate an increase in mitral valve gradient and right ventricular systolic pressure during exercise.
View Answer
18. Answer: E. This patient with mitral stenosis has a valve area of ≤1.5 cm2 with a gradient of 5 mm Hg and mild pulmonary hypertension. In asymptomatic moderate mitral stenosis, there is an indication to perform stress echocardiography to evaluate a rise in mean mitral valve gradients or an increase in pulmonary pressures of >15 mm Hg or >60 mm Hg. If patients have valve morphology amenable to valvuloplasty and meet these criteria, then there is an indication for percutaneous balloon mitral valvuloplasty.
19. A 60-year-old man with a history of hypertension and hypercholesterolemia has a routine follow-up with a new primary care physician who hears a holosystolic murmur at the apex radiating to the axilla. The patient did not have a history of fever, weight loss, recent trauma to the chest, or rheumatologic illness. He noted difficulty working in his garden because of fatigue. At the end of the visit, he remembered that on a previous health physical examination for the Army he was told that he had a murmur. A transthoracic echocardiogram revealed severe mitral regurgitation but was unable to elucidate the mechanism of mitral regurgitation. After being referred to a cardiologist, a 2D and 3D transesophageal echocardiogram (TEE) was
performed. Figure 5-4 is a view from a left atrial perspective demonstrating the mitral valve from a surgeon’s view. Which segment of the mitral valve is the cause of the mitral regurgitation?
performed. Figure 5-4 is a view from a left atrial perspective demonstrating the mitral valve from a surgeon’s view. Which segment of the mitral valve is the cause of the mitral regurgitation?
A. A1.
B. A2.
C. P1.
D. P2.
E. P3.
 Figure 5-4 |
View Answer
19. Answer: D. The abnormal scallop in this case is the P2 scallop. The P2 scallop is most frequently affected and is typically across from the aorta (Fig. 5-21) (Ao, Aorta; LAA, left atrial appendage).
 Figure 5-21 |
20. What is the mechanism of mitral regurgitation in this patient?
A. Bacterial endocarditis with a vegetation on the P2 scallop.
B. Barlow disease.
C. Rheumatic heart disease.
D. Systemic lupus erythematosus (SLE) with P2 Libman-Sacks lesion.
E. Flail P2 scallop.
View Answer
20. Answer: E. This is a P2 scallop that is flail (Fig. 5-22). The tip of the ruptured chordae can be seen from this left atrial perspective, noted by the arrows.
 Figure 5-22 |
21. A 75-year-old woman with a history of a mitral valve replacement, hypertension, and hypercholesterolemia presents with progressive shortness of breath, lower extremity edema, and palpitations. She has been faithfully taking all her medications including warfarin. Her blood pressure is 180/100 mm Hg, heart rate is 100 beats/min, and on auscultation, she has loud mechanical heart sounds and a 2/6 diastolic and systolic murmur at the apex. From the TEE demonstrated in Figure 5-5, what type of mechanical valve does she have?
A. Bioprosthetic valve.
B. Homograft.
C. Ball-cage valve.
D. Single tilting disc valve.
E. Bileaflet tilting disc valve.
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