3D Echocardiography

1. Just fancy pictures or added value ?

2. Other Side of Picture

4. Why 3D Echocardiography?
▪ 3D structure of the heart and relation of various structures
▪ Easier to demonstrate to those who are echo-challenged
▪ No need to rely on geometric assumptions when
quantifying volumes, mass, function
▪ Potentially faster image acquisition
• Presentation of realistic views of heart valves
• Volumetric evaluation of regurgitant lesions and shunts
with 3DE color Doppler imaging
• 3DE stress imaging

9. Fully Sampled Matrix-Array Transducers
▪ Development of fully sampled matrix-array
transducers in 2000.
▪ Currently, 3DE matrix-array transducers are
composed of nearly 3,000 piezoelectric
elements
Frequencies
▪ TTE 2-4 MHZ
▪ TEE 5-7 MHz
▪ Single transducer to acquire both 2D and 3DE
studies.

11. 2D Image Optimization
Mode Selection
Adjustments
Final display
Online/Offline analysis
Real-time or live
3DE imaging
Live 3D
(Narrow)
Live 3D
zoomed
Live 3D
(full volume)
Live 3D color
Doppler
Multiple-beat
3DE imaging
.
Modes

12. Narrow angle/Zoomed
•Valves
• Inter-atrial septum
• Inter-ventricular septum
Wide angle/Multi-beat
• LV
• RV
•Whole heart
What Acquisition Mode To Choose?

13. Single Beat
•Advantage
–Overcomes limitations from rhythm disturbances and
respiratory motion
•Disadvantage
–Limited by poor temporal resolution
Multi-beat
•Advantage
–Images with higher temporal resolution
•Disadvantage
–Gated images are susceptible to artifacts from respiratory
motion or cardiac arrhythmias
Single or Multi-beat?

14. Multiplane Mode (X-Plane)
Not true 3D modality
Dual screen to simultaneously display two real-time images.
– Rreference plane
– Lateral plane
▪ 30 to 150 degrees from the reference plane.
▪ Multiplane imaging in the elevation plane is also available.
▪ Color flow Doppler imaging can also be superimposed onto
the 2D images.

21. Real-Time 3D Mode—Narrow Sector
▪ Real-time display of a 30 x 60 degrees pyramidal volume.
▪ Narrow sector --- insufficient to visualize the entirety of a
single structure in any one imaging plane
▪ Superior spatial and temporal resolution
▪ Easy to use
▪ Better for valves and small structures

26. 3D ZOOM (Focused,Wide Sector)
▪ Focused to area of interest
▪ Wide sector view of cardiac structures
▪ Better for valves and IAS
▪ Decreased spatial and temporal resolution relative to real-time 3DE
▪ Used to cardiac interventions
▪ Best to visualize valves

42. Full Volume—Gated Acquisition
▪ Largest acquisition sector possible
▪ (up to 100° x 100°)
▪ Optimal spatial resolution
▪ High temporal resolution (30 Hz).
Similar to the real-time 3D and the
focused wide sector—“ZOOM”
modalities
▪ Cropping and off-line analysis. (Top) Example of electrocardiographically triggered multiple-beat 3DE data acquisition from a transthoracic apical window. Narrow
pyramidal volumes from four cardiac cycles (top left) are stitched together to form a single volumetric data set (top right). (Bottom)
Real-time or live 3DE single-beat acquisition of the whole heart (bottom left) and the left ventricle (bottom right) from the
transthoracic apical window.

43. Full Volume—Gated Acquisition
▪ Multiple-beat 3D echocardiography
– Higher temporal resolution
– Multiple acquisitions of narrow volumes
of data over several heartbeats that are
subsequently stitched together to
create a single volumetric data set
– Prone to imaging artifacts created by
patient or respiratory motion or
irregular cardiac rhythms.

45. Full Volume with Color Flow Doppler
▪ 3D plus Color
▪ Initially only for Full volume mode with 7-14 beats volume
stitched together.
▪ Currently 3D color full volume can be acquired with as low as
single beats but at the cost of temporal resolution.
▪ Used for quantification of regurgitant jets

48. Limitations
▪ Poor spatial and temporal resolution
▪ Currently, live 3DE color Doppler acquisition is limited to small
color Doppler volumes, usually with limited temporal resolution of
10 to 15 voxels/sec.
▪ Alternatively, multiple-beam full-volume acquisition of color
Doppler providing larger color Doppler volumes and volume rates
(up to 40 voxels/sec) are limited by stitching artifacts.

52. Challenges with 3DE Acquisition
TemporalVersus Spatial Resolution
▪ The main trade-off in 3DE imaging is between
volume rate (i.e., temporal resolution) and
spatial resolution.
▪ Fortunately, imaging volumes can be adjusted in
size (i.e., made smaller) to increase volume rate
while maintaining spatial resolution.

53. ▪ Gated data sets are most challenging in
patients with arrhythmias and/or
respiratory difficulties.
▪ ECG tracing needs to be optimized to
obtain a distinct R wave
▪ Stitching artifacts
Challenges with 3DE Acquisition
ECG Gating and Breath Hold

54. “suboptimal 2D images result in suboptimal 3DE data sets.”
3D Optimization

55. 3D Optimization

56. Offline Analysis

57. 3DE Image Display: Cropping
▪ Cropping is inherent to 3D echocardiography.
▪ Different fromTomography
▪ From difficult cross sectional views to surgical
views
▪ Cropping can be performed either during
procedure or later
▪ Advantages of cropping during procedure

58. Multiplanar reconstruction of a rheumatic, stenotic mitral valve imaged with zoomed, transesophageal 3D echocardiography (bottom
right). Orthogonal cut planes through the narrowest mitral valve orifice in mid-diastole (top left and right) with a perpendicular plane
providing an en face image for mitral valve area (MVA) measurement (bottom left).

59. Post-Acquisition Display
Once a 3DE data set is acquired, it can be viewed interactively using a
number of 3D visualization and rendering software packages.
Display of 3DE images can be divided into three broad categories:
(1) volume rendering
(2) surface rendering (including wireframe display
(3) 2D tomo- graphic slices
The choice of the display technique is generally determined by the
clinical application.

60. Volume Rendering
▪ Volume rendering is a technique that uses different types of
algorithms to preserve all 3DE information and project it, after
processing, onto a 2D plane for viewing.
▪ Volume-rendered 3DE data sets can be electronically segmented and
sectioned.
▪ To obtain ideal cut planes, the 3D data set can be manipulated,
cropped, and rotated.
▪ Volume rendering provides complex spatial relationships in a 3D
display that is particu- larly useful for evaluating valves and adjacent
anatomic structures.

61. From a transthoracic 3DE data set of the left ventricle (left), the LV endocardium can be traced (middle, top) to obtain the LV
volume throughout the cardiac cycle (right, top). As well, the LV endocardium can be divided according to the 17-segment
model (middle, top), and the time each segment requires to attain minimal volume in the cardiac cycle can be identified (right,
bottom).

63. Surface Rendering
▪ Visualization technique that shows the surfaces of
structures or organs in a solid appearance.
▪ Select structure (LV, RV, Atria)
▪ Trace Manually or automated
▪ Construction and display (Wire frame or 3D)
▪ Mostly volume and surface rendering are combined to get
full details

66. The RV volume can be determined from 3D echocardiographic data sets by the method of disks (left). Other methods include
dynamic endocardial tracking with end-diastolic volumes presented by the mesh shell and end-systolic volumes presented by the
solid shell (middle). The RV endocardial shell can be segmented for regional analysis (right).

67. 2D Tomographic Slices
▪ The volumetric data set is sliced or cropped to
obtain multiple simultaneous 2D
▪ Multiple levels and unique cuts
▪ Different planes like orthogonal or parallel planes
▪ Uniformly spaced cuts
▪ Accurate assessment of dimensions of chambers,
valves or defect
▪ Simultaneous orthogonal slides in ONE cardiac
cycle

77. Just fancy pictures
or
Added value ?

78. Thanks for your patience

81. LimitationsAlthough RT3DTEE represents an important step in perioperative
imaging, significant imitations remain. First, while 3D zoom and live 3D are indeed real-
time modes, the acquisition of a 3D full volume as well as a 3D color full volumes are
based on automatic reconstruction from subvolumes and are therefore prone to
artifacts from arrhythmias, and ventilation – the socalled stitch artifacts. Second, as 3D
echo obeys the same physical laws as 2D, poor 2D image quality will likely translate in
similarly poor 3D image quality. Unlike the mitral valve, other structures in the far field
like the aortic and tricuspid valves are more difficult to visualize using current
technology.Third, direct measurements (e.g. caliper, trace) cannot be performed
directly in 3D images and require the use of time-consuming software. Fourth,
although the built-in software features quantitative assessment of the mitral valve and
left ventricle, it would benefit from a more user-friendly interface. Finally, as with most
new technology, RT3DTEE will prolong a comprehensiveTEE examination, especially
when quantitative techniques are employed. However, in the future and with further
improvements in technology, RT3DTEE may help to Fig 4: 3DTEE en-face view of a
mechanical bileaflet prosthesis in the mitral position with an Amplatzer occluding
device positioned to seal a paravalvular leak (arrow). Page 6 of 6 even expedite a
comprehensiveTEE examination by using a single 3D view of the mitral valve rather
than the five conventional 2D views.

82. • Live 3D: displays a pyramidal dataset with dimensions of approximately 50° x 30° that can be used to
display cardiac structures located in the near field. •.

84. • FullVolume: that allows the inclusion of a larger cardiac volume.The wide angle data set
is compiled by merging four to seven narrower RT-3D pyramidal wedges obtained over
four to seven heartbeats. Imaging artifacts may be avoided in the anesthetized patient by
suspending ventilation and avoiding electrocautery use during acquisition of the full
volume sequence.Therefore, it is desirable to acquire full volume loops at the beginning of
the comprehensiveTEE-exam in the operating room prior to the start of surgery.A full
volume loop of the left ventricle is based on the 2D midesophageal four chamber view.
When selected, the full volume mode displays a biplane image with the four chamber view
and the (perpendicular plane) corresponding orthogonal image.The 3D-volume is
displayed as a 50% cropped volume mirroring the four chamber view.This is necessary
since the full volume image at the outset will not display intraventricular structures like
valves, papillary muscles etc. Resetting the crop plane however, allows the whole
pyramidal dataset to be displayed.The full volume can be further processed offline by
rotating and cropping to visualize specific intracardiac structures. Cropping can be
performed by either using one of six available cropping planes selected from a 3D cropping
box or by using a freely adjustable plane. Acquired full volumes can also be used for
volumetric quantification of the LV using available built-in software (QLAB, Philips Medical
Systems,Andover, MA).

85. • 3D Color FullVolume: Similar to the acquisition of a full
volume the wide angle data set is compiled by merging 7 to 14
narrower RT-3D pyramidal wedges and is similarly prone to
artifacts introduced by arrhythmias, movement, or
electrocautery. For this mode it is essential to place the area of
interest, for example, the regurgitant jet, in the center of the
sector.The remainder of the acquisition is identical to that
used for full volume acquisition. In the newer software release,
the color full volume may be acquired using 1, 2, 4 or 6
separate slices.Once again, one must balance the need for
optimal frame rates (more slices) with the tendency for stitch
artifacts.