The two-dimensional echocardiographic exam

Question 1

Why shaving on both sides of the thorax?

Answer 1

To minimize the effects of air on sound transmission and improve skin contact.
Shave the right 4th to 6th intercostal spaces in dogs and 3rd to 5th intercostal spaces in cats. The left side should be shaved from about the 4th intercostal space to just past the last rib in all small animals. From the costochondral junction to the sternum.

Question 2

Images are obtained by scanning from beneath the table since this method of examining the heart routinely produces better images. The heart drops down toward the thoracic wall creating less of a problem with lung interference on echo images. It also allows a higher frequency transducer to be used during many exams, since less depth penetration is necessary.

Answer 2

Images are obtained by scanning from beneath the table since this method of examining the heart routinely produces better images. The heart drops down toward the thoracic wall creating less of a problem with lung interference on echo images. It also allows a higher frequency transducer to be used during many exams, since less depth penetration is necessary.

Air interference from the lung is even more of a problem when the animal is placed in left lateral recumbency (or standing).

Question 3

Transducer frequency is an important consideration since it affects depth of penetration and resolution of the image. Higher frequency transducers, because of their shorter wavelengths, allow better ……….. of structures but less depth …………

Answer 3

Transducer frequency is an important consideration since it affects depth of penetration and resolution of the image. Higher frequency transducers, because of their shorter wavelengths, allow better resolution of structures but less depth penetration.

Question 4

Low-frequency transducers, with …………. wavelengths, allow sound waves to travel deeper into tissues before weakening. This is at the expense of ………….

Answer 4

Low-frequency transducers, with longer wavelengths, allow sound waves to travel deeper into tissues before weakening. This is at the expense of resolution.

Question 5

High frequency transducers create high-resolution images. Try higher frequency transducers before selecting a lower one just to see if it will work.

Answer 5

High frequency transducers create high-resolution images. Try higher frequency transducers before selecting a lower one just to see if it will work.

Question 6

Use a …….. frequency transducer to obtain clearer images of near field structures.

Answer 6

Use a high frequency transducer to obtain clearer images or near field structures.

Question 7

Even though depth and resolution are inverse components of transducer frequency, when an appropriate transducer is used, the loss in resolution is not appreciated because structures are larger.

Answer 7

Even though depth and resolution are inverse components of transducer frequency, when an appropriate transducer is used, the loss in resolution is not appreciated because structures are larger.

High frequency transducers should be used for cats and small dogs. A high frequency transducer can also be used in larger animals in order to improve the resolution of near field structures, like the tricuspid valve.

Question 8

Medium-sized animals in the range of approximately 30-50 pounds can often be images with 7.5 to 5.0-MHz transducers. larger dogs usually require a ……. -MHz or lower frequency transducer.

It is a good habit to try the highest frequency you have before selecting a lower one just to see if it works.

Answer 8

Medium-sized animals in the range of approximately 30-50 pounds can often be images with 7.5 to 5.0-MHz transducers. larger dogs usually require a 5.0-MHz or lower frequency transducer.

It is a good habit to try the highest frequency you have before selecting a lower one just to see if it works.

Even though an animal weights 60 pounds, for ex, a very narrow thorax may allow the use of a 7.5-MHz transducer and produce excellent images.

(large animals like the adult horse/cow almost always require a 2.5 Mhz or lower frequency transducer for the sound beams to reach the far wall of the heart).

Question 9

Switch to a ………… frequency transducer when starting the Doppler part of your exam in order to obtain better quality Doppler info.

Answer 9

Switch to a lower frequency transducer when starting the Doppler part of your exam in order to obtain better quality Doppler info.

Question 10

Apical four-and five-chamber examination planes sometimes require changing the probe to …………….. frequency than used to image the patient’s heart for standard right or left parasternal planes through the heart.

Answer 10

Apical four-and five-chamber examination planes sometimes require changing the probe to slower frequency than used to image the patient’s heart for standard right or left parasternal planes through the heart.

Imaging from the apex of the heart to its base requires much more depth penetration than views that image the width of the heart from right to left or vice versa across the thorax.

Question 11

Even when all imaging planes can be obtained with one transducer, change to a …….. transducer frequency when obtaining Doppler flow information.

Answer 11

Even when all imaging planes can be obtained with one transducer, change to a lower transducer frequency when obtaining Doppler flow information.

Lower frequency transducers provide increased signal strength at greater depths and reduce aliasing during pulsed-wave and color-flow Doppler interrogation. Lower transducer frequencies are also often required to produce a strong enough spectral signal from small regurgitant volumes. Most equipment automatically switches to a lower frequency when Doppler is used.

Question 12

2D echo uses transducers that transmit multiple beams of sound in the form of….?

Answer 12

In the form of a sector or pie. The sector has width, depth. and thickness. Although section thickness is sometimes a factor in image quality, it is not a consideration when describing real-time anatomy.

Question 13

As the sector of sound is sent through the heart, soft tissue reflects sound back to the transducer and appears ……… on the monitor.

The fluid-filled spaces of the cardiac chambers lack the density to reflect sound. These areas appear …….. on the ultrasound monitor.

Answer 13

As the sector of sound is sent through the heart, soft tissue reflects sound back to the transducer and appears white on the monitor. The fluid-filled spaces of the cardiac chambers lack the density to reflect sound. These areas appear black on the ultrasound monitor.

Question 14

Longitudinal (sagittal) images are those in which the imaging plane follows the length of the heart from base to apex and are often referred to as ……….. views.

Answer 14

Longitudinal (sagittal) images are those in which the imaging plane follows the length of the heart from base to apex and are often referred to as long-axis views.(Figure 2.8)

Question 15

Transverse images are those in which the imaging plane shows the width of the heart from right to left, and these are usually referred to as …………. views.

Answer 15

Transverse images are those in which the imaging plane shows the width of the heart from right to left, and these are usually referred to as short-axis views.
Figure 2.9.

Question 16

Long axis: Sagittal imaging planes that follow the length of the heart.

Answer 16

Long axis: sagittal imaging planes that follow the length of the heart.

Question 17

Short axis: Transverse imaging planes that follow the width of the heart.

Answer 17

Short axis: Transverse imaging planes that follow the width of the heart.

Question 18

Apical two-, four-, and five-chamber images can be obtained from left parasternal or subcostal transducer positions. There are also several longitudinal and oblique planes that require imaging from the left side of the animal. It is easiest to obtain the left parasternal views when small animals are placed in left lateral recumbency on the table.

Answer 18

Apical two-, four-, and five-chamber images can be obtained from left parasternal or subcostal transducer positions. There are also several longitudinal and oblique planes that require imaging from the left side of the animal. It is easiest to obtain the left parasternal views when small animals are placed in left lateral recumbency on the table.

Question 19

Image orientation:

Long axis: base of the heart to the right side of the sector image.

Short/transverse axis: pulmonary artery to the right side of the sector image.

Apical: left ventricle to the right side of the sector image.

Answer 19

Image orientation:

Long axis: base of the heart to the right side of the sector image.

Short axis: pulmonary artery to the right side of the sector image.

Apical: left ventricle to the right side of the sector image.

Question 20

Image orientation:
Recommendations made by the Echocardiography Committee of the Specialty of Cardiology/American College of Veterinary Internal Medicine.

Answer 20

Image orientation:
Recommendations made by the Echocardiography Committee of the Specialty of Cardiology/American College of Veterinary Internal Medicine.

Question 21

Transducer reference mark: Value of this?

Answer 21

This serves two purposes:

1. Identifies how the sound beam leaves the transducer: A 2D sector of sound with width and depth is generated along the diameter or length of the transducer face indicated by the reference mark.
2. Provides orientation for structures on the sector image: Every ultrasound machine displays a symbol on the top right or left of the sector image (Fig 2.11). Whatever the reference mark is directed toward in the body during an exam will be seen on the side of the sector image with the symbol.
   For ex; if the reference mark is directed toward the base of the heart while looking at a parasternal long-axis image, the atria and aorta will be seen on the side of the image with the symbol.

The standard protocol for cardiac imaging requires the reference symbol to be displayed on the right side of the sector image.

Question 22

Rotating the transducer means?

Answer 22

Twisting it clockwise or counterclockwise about its length. Fig 2.12

Question 23

Pointing the transducer involves?

Answer 23

Directing the transducer face (or crystals) toward the anatomic structure that is named. The transducer is not rotated during this movement, remains in the same place on the thorax, and the same transducer angle with reference to the animal is maintained. (Do not lift or drop the transducer in this move.

Fig 2.13.

Question 24

Lifting or dropping the transducer involves bringing it up toward the exam table or dropping it down away from the table, making the angle between the transducer and animal smaller or larger, respectively. The transducer remains in the same location on the thorax, the crystal direction remains the same, the transducer is not rotated.

Answer 24

Lifting or dropping the transducer involves bringing it up toward the exam table or dropping it down away from the table, making the angle between the transducer and animal smaller or larger, respectively. The transducer remains in the same location on the thorax, the crystal direction remains the same, the transducer is not rotated.

When the probe is lifted up toward the table, the sound beams become more parallel to the animal and a smaller angle is created between the transducer and the animal.
Dropping the problem away from the table creates a larger angle between the animal and the transducer and orients the sound plane more perpendicularly to the animal.

When lifting or dropping: Do not change where the crystals are pointing.

Question 25

The pericardium is a very echo dense bright line around the heart. This echogenicity is due….?

Answer 25

Due to the great difference in acoustical impedance between pericardial tissue and lungs.

Question 26

Right parasternal long axis images: Some of the terminology used to discuss echocardiographic structure comes from the human side. Anterior is used to describe….?
Posterior refers to?

Answer 26

Anterior: Things closer to the transducer.

Posterior: Things farther away from the transducer.

This is because of the heart’s position in the human thorax.

Question 27

Right parasternal long axis images: The transducer is positioned over the heart from a ventral aspect and this is ……, while the spine is ……..

Answer 27

The transducer is positioned over the heart from a ventral aspect and this is anterior, while the spine is posterior.

Fig 2.16

Question 28

Right parasternal long axis images: The top wall of the aorta is referred to as the anterior wall, and the bottom and the bottom wall of the aorta is referred to as the posterior wall because of their location with reference to the body.

Answer 28

The top wall of the aorta is referred to as the anterior wall, and the bottom and the bottom wall of the aorta is referred to as the posterior wall because of their location with reference to the body.

Question 29

Most ultrasound machines use LVPW, which stands for ………………, when referring to the left ventricular free wall.

Answer 29

Most ultrasound machines use LVPW, which stands for left ventricular posterior wall, when referring to the left ventricular free wall.

Question 30

Crystals?

Answer 30

The end of transducer that emits the sound waves.

Question 31

Right parasternal long axis images: The IVS and anterior aortic wall are continuous in this plane throughout the heart. The membranous portion of the IVS is seen where the muscular septum becomes a thin white line just proximal to the aorta. The aortic valve cusps seen just to the right of this junction are curved semilunar lines concave to the aorta (Fig 2.17).

Answer 31

Right parasternal long axis images: The IVS and anterior aortic wall are continuous in this plane throughout the heart. The membranous portion of the IVS is seen where the muscular septum becomes a thin white line just proximal to the aorta. The aortic valve cusps seen just to the right of this junction are curved semilunar lines concave to the aorta (Fig 2.17).

Question 32

Right parasternal long axis images: The anterior (septal) mitral valve (MV) leaflet extends into the left ventricular chamber and is continuation of the posterior aortic wall. The shorter mural (posterior) MV cusp is at the junction of the muscular LVW and thin left atrial wall.

Answer 32

The anterior (septal) mitral valve (MV) leaflet extends into the left ventricular chamber and is continuation of the posterior aortic wall. The shorter mural (posterior) MV cusp is at the junction of the muscular LVW and thin left atrial wall. (Fig 2.16)

Question 33

Right parasternal long axis images: A small circular structure that may be seen at the base of the left atrium is a transverse section of the ……………………

Answer 33

A small circular structure that may be seen at the base of the left atrium is a transverse section of the right pulmonary artery.

Question 34

Right parasternal tipped (apex up) long-axis left ventricular outflow view in a dog: Fig 2.19

Answer 34

Right parasternal tipped (apex up) long-axis left ventricular outflow view in a dog: Fig 2.19

Tipped or somewhat apical long-axis views are also generated from this side of the thorax.
The same structures are visible, but the apex of the heart is seen toward the top left of the sector image while the atria are seen to the bottom right. (Fig 2.19, 2.20)

Question 35

An outflow image that optimizes the aorta, the aortic valve, and the left ventricular outflow tract can be obtained by slight movement of the transducer away from the inflow outflow view: dropping the transducer away from the thorax slightly brings the aortic valve cusps clearly into view.

Answer 35

An outflow image that optimizes the aorta, the aortic valve, and the left ventricular outflow tract can be obtained by slight movement of the transducer away from the inflow outflow view.

The mitral valve and left atrium and left atrium are not seen well in this imaging plane, and the free wall papillary muscle is usually prominent, but all other structures remain the same. (Fig 2.21)

Question 36

Right parasternal long axis: The transducer is close to the sternum in cats and small dogs but farther away from the sternum in larger dogs.

Answer 36

Right parasternal long axis: The transducer is close to the sternum in cats and small dogs but farther away from the sternum in larger dogs.

Question 37

The feline heart is positioned in its thorax so that the …………. axis is aligned more with the sternum.

Answer 37

The feline heart is positioned in its thorax so that the long axis is aligned more with the sternum.
Because of this, the transducer is located very close to the sternum with an angle between the cat and the transducer that can approach 30 grader (symbol).
(Fig 2.24)

Question 38

Right parasternal short-axis images: Transverse images of the heart may be obtained at any level from the base to the apex. Five standard images are taken in the transverse plane: which ones?

Answer 38

The left ventricle
The chordae tendinae
The mitral valve
The heart base with aorta
The high heart base with pulmonary artery
(Fig 2.39).

In the small animal an additional angled view through the long axis of the pulmonary artery with an oblique view of the left ventricle is also presented here. This plane is between the longitudinal and short axis.

Question 39

Fig 2.43: Se APM och PPM

Answer 39

Anterior and posterior papillary muscle

Question 40

Left ventricle with papillary muscles and chord tendinae view: The papillary muscle on the left side of the transverse image is the …………… papillary muscle, while the papillary muscle to the right side of the transverse image is the ……………. papillary muscle.

Answer 40

The papillary muscle on the left side of the transverse image is the subatrial papillary muscle, while the papillary muscle to the right side of the transverse image is the subauricular papillary muscle.

Question 41

Slight movement of the transducer toward the base of the heart shows chord tendinae at their attachment points on the papillary muscles.

Answer 41

Fig 2.44: Slight movement of the transducer toward the base of the heart shows chord tendinae at their attachment points on the papillary muscles.

Question 42

Left ventricle with papillary muscles and chord tendinae view: An egg-shaped ventricle means the transducer has not been turned enough or it has been turned too much (Figure 2.46). Rotate it back and forth until the most circular shape is seen.

Answer 42

An egg-shaped ventricle means the transducer has not been turned enough or it has been turned too much (Figure 2.46). Rotate it back and forth until the most circular shape is seen.

The further back toward the apex of the heart the transducer is positioned when obtaining transverse sections the less right ventricle you will see. This usually happens when the starting long-axis plane before twisting to transverse views was a tipped view.

Question 43

Mitral valve view: Pointing the transducer crystals more toward the base of the heart brings the mitral valve into view.

Answer 43

Mitral valve view: Pointing the transducer crystals more toward the base of the heart brings the mitral valve into view.

Question 44

Short axis: Mitral valve view. Poitning the transducer crystals more toward the base of the heart brings the mitral valve into view. The leaflets will appear as an oval within the left ventricular chamber when open and as touching lines when they are closed during systole. Fig 2.48. “Fish mouth”.
The top leaflet in the fish mouth is the ………. leaflet, and the leaflet that lies close to the left ventricular wall is the ……. leaflet.

Answer 44

The top leaflet in the fish mouth is the septal leaflet, and the leaflet that lies close to the left ventricular wall is the mural leaflet.

A larger portion of the right ventricle can now be seen above the left ventricle at the top of the sector image.

Question 45

Heart base: Aorta and left atrium view: The image of closed valve leaflets in this plane is often called the “Mercedes sign”.

The cusp that is located at the junction of the atrial septum is the ………… cusp.
The cusp located next to the right ventricular chamber is the ……………….. cusp, and the cusp positioned just above the left atrium and next to the left auricle is the ………………. cusp.

Answer 45

The cusp that is located at the junction of the atrial septum is the non coronary cusp.
The cusp located next to the right ventricular chamber is the right coronary cusp, and the cusp positioned just above the left atrium and next to the left auricle is the left coronary cusp.

Question 46

Heart base: Aorta and left atrium view: The pulmonary valve if visible on this view may be seen anywhere from 3 to 5 o’clock. In cats this valve is located a little higher on the sector image, closer to the 2- to 3-o-clock location.

Answer 46

Heart base: Aorta and left atrium view: The pulmonary valve if visible on this view may be seen anywhere from 3 to 5 o’clock. In cats this valve is located a little higher on the sector image, closer to the 2- to 3-o-clock location.

Question 47

Heart base: Aorta and left atrium view: The main pulmonary artery extends downward from the valves, but only a portion of it is seen since the ……………., a wedge-shaped extension of the left atrium is seen just below the pulmonary valve.

Answer 47

The main pulmonary artery extends downward from the valves, but only a portion of it is seen since the left auricle, a wedge-shaped extension of the left atrium is seen just below the pulmonary valve.

Question 48

Heart base: Aorta and left atrium view: The interatrial septum, seen at the left side of the image, separates the two atria. The shape of the left atrium and auricle has been described as a whale or tadpole with the left auricular appendage representing the tail of the whale or tadpole.

Answer 48

Heart base: Aorta and left atrium view: The interatrial septum, seen at the left side of the image, separates the two atria. The shape of the left atrium and auricle has been described as a whale or tadpole with the left auricular appendage representing the tail of the whale or tadpole.

Question 49

Heart base: Aorta and left atrium view:
………… arteries can be seen leaving the sinus of Valsalva if the transducer is tilted and rotated slightly at the level of the aortic valves.

Answer 49

Coronary arteries can be seen leaving the sinus of Valsalva if the transducer is tilted and rotated slightly at the level of the aortic valves.

Question 50

Heart base: Aorta and left atrium view:
The ……. coronary artery can be seen near the junction of the aorta, left auricle, and pulmonary artery. Fig 2.52.

The …… coronary artery may be seen coming from the area of the ……. coronary cusp above the pulmonary valve to the top right side of the sector image.

Answer 50

The left coronary artery can be seen near the junction of the aorta, left auricle, and pulmonary artery. Fig 2.52.

The right coronary artery may be seen coming from the area of the right coronary cusp above the pulmonary valve to the top right side of the sector image.

Question 51

Heart base: Aorta and left atrium view: Slight rotation of the transducer allows both cross-sectional and longitudinal images of the arteries to be seen. Fig 2.53.

Answer 51

Slight rotation of the transducer allows both cross-sectional and longitudinal images of the arteries to be seen. Fig 2.53.

Question 52

Heart base: Aorta and left atrium view: Point the transducer crystals even more toward the neck (heart base), and the aorta will appear in the middle of the image. Fan and twist the transducer back and forth until all three aortic valve cusps are seen. If the intertribal septum and the left auricle are not seen clearly, twist the transducer so the reference mark moves a little more to the sternum. At this point there is often air interference in the image. Try to clean up the image by slowly sliding the transducer around the intercostal space (circling as described earlier).

Answer 52

Heart base: Aorta and left atrium view: Point the transducer crystals even more toward the neck (heart base), and the aorta will appear in the middle of the image. Fan and twist the transducer back and forth until all three aortic valve cusps are seen. If the intertribal septum and the left auricle are not seen clearly, twist the transducer so the reference mark moves a little more to the sternum. At this point there is often air interference in the image. Try to clean up the image by slowly sliding the transducer around the intercostal space (circling as described earlier).

Question 53

Heart base: Pulmonary artery view.

Slightly further toward the base of the heart is the fifth plane; which shows the pulmonary artery in its length up to and including its bifurcation into the ………………. (Fig 2.54, 2.55)

Answer 53

Slightly further toward the base of the heart is the fifth plane; which shows the pulmonary artery in its length up to and including its bifurcation into the right and left main pulmonary arteries. (Fig 2.54, 2.55).

The pulmonary valve is located to the right of the image anywhere from 2 to 4 o’clock. Only a small portion of the LA is now visible between the right atrium and right pulmonary artery branch at about 8 and 9 o’clock on the image. The bifurcation is usually seen between 5 and 6 o’clock on the sector.

Question 54

Heart base: Pulmonary artery view.
The …….. main pulmonary artery extends from right to left under the ascending aorta. The …… main pulmonary artery however is just barely seen past the bifurcation as it extends into the lung field.

Answer 54

The right main pulmonary artery extends from right to left under the ascending aorta. The left main pulmonary artery however is just barely seen past the bifurcation as it extends into the lung field.

Question 55

Heart base: Pulmonary artery view.
Once a good image of the heart base with aorta, left atrium, and left auricle is seen, the crystals are tilted just a little more toward the heart base in order to bring the main pulmonary artery into view.

Answer 55

Once a good image of the heart base with aorta, left atrium, and left auricle is seen, the crystals are tilted just a little more toward the heart base in order to bring the main pulmonary artery into view.

The rest of the image may not be clear but the pulmonary valve and the bifurcation should be.

Question 56

Left ventricle with pulmonary artery view (right parasternal oblique axis): This oblique right parasternal image is generated at the level of the left ventricle. Slight dropping of the transducer allows us to see the pulmonary artery running along the right side of the image next to an egg-shaped left ventricle.

Answer 56

Left ventricle with pulmonary artery view: This oblique right parasternal image is generated at the level of the left ventricle. Slight dropping of the transducer allows us to see the pulmonary artery running along the right side of the image next to an egg-shaped left ventricle.

Fig 2.56

Question 57

2.53: Transverse plane through the heart base in horse shows a sagittal view of a coronary artery as i t leaves the aorta.

Answer 57

2.53: Transverse plane through the heart base in horse shows a sagittal view of a coronary artery as i t leaves the aorta.

Question 58

Left parasternal apical images:

From the apical five-chamber view towards apical four-chamber view.

Answer 58

Left parasternal apical images:
From the apical five-chamber view towards apical four-chamber view.

Slight movement of the transducer allows visualization of much more of the right side of the heart as the apical four-chamber plane is seen. Fig 2,62.
The aorta is no longer seen, instead the intertribal septum is now located between the left and right atria.

In cats the transducer is usually aligned more parallel to the length of the body than in the dog, and the angle between the transducer and the body wall is small enough that the transducer often hugs the body wall. Fig 2.65.

Question 59

When the apex of the heart is located to the right side of the image instead of at the top of the sector, the transducer face is directed too much toward the spine when it should be pointed more toward the head and legs.

Answer 59

When the apex of the heart is located to the right side of the image instead of at the top of the sector, the transducer face is directed too much toward the spine when it should be pointed more toward the head and legs. Fig 2.64.

The transducer is aligned very parallel with the body of a cat in order to obtain apical views.

Question 60

Left parasternal cranial long-axis images: Left cranial left ventricular outflow view.

The left parasternal left ventricular outflow view is the reference plane for this side of the thorax. This image is obtained from a very cranial transducer position and looks very similar to the right parasternal long-axis left ventricular inflow outflow view except that the tricuspid valve is not seen.
Instead, the ……………… is seen above the ascending aorta. This view is excellent for observing the aortic valve and ascending aorta.
Images still maintain the base of the heart to the ……..and apex to the …….. orientation.

Answer 60

This image is obtained from a very cranial transducer position and looks very similar to the right parasternal long-axis left ventricular inflow outflow view except that the tricuspid valve is not seen.
Instead, the pulmonary valve is seen above the ascending aorta. This view is excellent for observing the aortic valve and ascending aorta.
Images still maintain the base of the heart to the right and apex to the left orientation.

Fig 2.66

The left 3rd to 4th intercostal spaces are used for this image. The transducer is 2 to 3 inches away from the sternum.

Question 61

Left parasternal cranial long-axis images:
Left cranial right atrium and auricle view.
Remaining in the cranial location and pivoting the beam slightly (drop the transducer down away from the animal) results in a plane that transect the right atrium, tricuspid valve, and right auricle. Fig 2,68. This image provides an oblique view of both ventricles, with an egg-shaped left ventricle on the top right of the sector image.

Answer 61

Left parasternal cranial long-axis images:
Left cranial right atrium and auricle view.
Remaining in the cranial location and pivoting the beam slightly results in a plane that transect the right atrium, tricuspid valve, and right auricle. Fig 2,68. This image provides an oblique view of both ventricles, with an egg-shaped left ventricle on the top right of the sector image.

The right atrial appendage extends to the right and up from the atrium. The caudal vena cava (CVC) may be seen as it enters the right atrium from the left side of the image.

Fig 2.67.

Question 62

Left parasternal cranial long-axis images:
Left cranial right ventricular outflow view. (the third plane to be generated from the left cranial transducer position): also requires slight fanning away from the left ventricular outflow plane. The right ventricular outflow tract and pulmonary valve are seen along the top and right of the image, with an oblique left ventricle and atrium along the bottom. Fig 2.69.

Answer 62

Left cranial right ventricular outflow view. (the third plane to be generated from the left cranial transducer position): also requires slight fanning away from the left ventricular outflow plane. As the transducer is raised up (toward the animal), the left ventricular outflow tract will disappear from view, and the pulmonic valve and right ventricular outflow tract will be seen to the right of the sector image.
The right ventricular outflow tract and pulmonary valve are seen along the top and right of the image, with an oblique left ventricle and atrium along the bottom. Fig 2.69.

The pulmonary artery extends downward from the valve along the right side of the image. A small piece of the aortic valve may be seen at the junction of the left ventricle and pulmonary artery. Fig 2.70. Other structures are often not clear in this more vertical image, but the pulmonary valve is imaged well, and this image provides excellent alignment with flow for Doppler interrogation.

Question 63

Left parasternal short-axis images:

Structures are the same as those seen in the right parasternal images but have different locations.

Answer 63

Left parasternal short-axis images:

Structures are the same as those seen in the right parasternal images but have different locations.

Question 64

Left parasternal short-axis images: Left cranial transverse heart base view.
Remaining in the left 4th or 5th intercostal space but twisting the transducer toward a transverse plane.

Answer 64

Left parasternal short-axis images: Left cranial transverse heart base view.
Remaining in the left 4th or 5th intercostal space but twisting the transducer toward a transverse plane. The aorta is still seen as a circle in the center of the image, and the right ventricle wraps over the top of the aorta. On the right side of the image the pulmonary artery curves around the aorta as it does in right parasternal images but the pulmonary valve is located at about 12 to 1 o’clock. The bifurcation of the main pulmonary artery into its branches is seen in this imaging plane. The tricuspid valve is found at about 8 to 9 o’clock. The right
This is a good plane for Doppler evaluation of the pulmonary artery and tricuspid valve.

Question 65

Left cranial left auricle view: Small animal: The left auricle is seen while fanning the transducer between the pulmonary valve and the tricuspid valve in the transverse left cranial imaging plane. slowly fan between the two valves, keeping the aorta in the image, and the left auricle is located on the right side of the image. In dogs, the tip of the auricular appendage is located at about 1 o’clock, while in cats, it often extends to 12 or 11 o’clock on the sector image.

Answer 65

Left cranial left auricle view: Small animal: The left auricle is seen while fanning the transducer between the pulmonary valve and the tricuspid valve in the transverse left cranial imaging plane. slowly fan between the two valves , keeping the aorta in the image, and the left auricle is located on the right side of the image. In dogs, the tip of the auricular appendage is located at about 1 o’clock, while in cats, it often extends to 12 or 11 o’clock on the sector image.

Fig 2.80

Question 66

Subcostal five-chamber image: This subcostal imaging plane shows the same structures that the parasternal apical five-chamber imaging plane does. Value of imaging from a subostal location?

Answer 66

Aligns the ascending aorta more parallel with a Doppler cursor allowing more accurate analysis of aortic flow (Fig 2.83).
The liver is seen at the top of the sector image, and the apex of the left ventricular chamber is just below the liver lobe.

The transducer should be held very parallel to the abdominal wall (Fig 2.84). This image usually requires a low frequency transducer.

Question 67

Two-dimensional imaging controls:
Depth controls adjust the field of view. Adjust the depth setting until the RT image fills the field in order to reduce the amount of lung field and reverberation artifact seen at the bottom of the sector. A cursor or other calibration system is typically displayed alongside the sector image. Each mark usually represents …….of depth.

Answer 67

1 cm

Question 68

Gain: Often called power or transmits on some machines. Gain controls the transducer´s…….

Answer 68

The transducer’s output power or signal strength. The entire sector image is affected by this control. Too high of a gain setting will produce a very white distorted image while too low of a setting will not produce a signal with enough strength to generate a good image. Fig 2.86.

Set the gain so the image is clearly seen with no “blooming” of pixels and the chambers contain no extraneous echoes.

Question 69

Time gain compensation (TGC) levers control what?

Answer 69

The gain settings at specific depths on the RT image. Fig 2.87

Gain is increased by sliding the lever to the right and decreased by sliding the lever to the left. This allows the stronger reflections from near-field structures to be toned down (attenuated) while deeper structures that reflect weaker sound can be intensified.

Typically there is a slight angle of the TGC sliders to the right as depth increases in order to amplify those echoes. No slider should be out of alignment with the one above or below it.

Question 70

Fig 2.88: Illustrates what can happen if one sliding lever is too far to the left and out of alignment with the others.

Answer 70

It will attenuate the displayed sound.

If an area of increased echogenicity or decreased echogenicity extends across the entire width of the sector image and is limited to a cm or 2 of depth on the image, the TCG curve may have a lever moved too far to the right or left.

Question 71

Compress/Dynamic range: Value of this?

Answer 71

Adjust the range of gray on the displayed image.

Question 72

………………… the compression level allows weaker echoes to be displayed and more shades of gray are visible.

Answer 72

Decreasing the compression level allows weaker echoes to be displayed and more shades of gray are visible.
A softer-looking image is created.

Question 73

……………. compression reduces the dynamic range, eliminates the display of grays associated with weaker signals, results in a higher contrast image, and reduces background noise. Fig 2.89.

Answer 73

Increasing compression reduces the dynamic range, eliminates the display of grays associated with weaker signals, results in a higher contrast image, and reduces background noise. Fig 2.89.
This is often personal preference but can enhance image quality if difficult to image patients.

Question 74

Persistence/Frame averaging: Value?

Answer 74

This control averages imaging frames by mixing info from old frames with new frames; resulting in a smoother image with less speckling.
Cardiac imaging generally employs little, if any persistence, since the RT effect becomes blurred with frame averaging.

Question 75

Sector widths: are typically adjustable from about ……… grader angle to a narrow width of less than ……… grader. Fig 2.90.

Answer 75

Sector widths: are typically adjustable from about 120 grader angle to a narrow width of less than 30 grader. Fig 2.90.

Question 76

The smaller the sector angle the ……………. the frame rate and the ……………. resolution of the RT image.

Answer 76

The smaller the sector angle the faster the frame rate and the higher resolution of the RT image.

Question 77

Focus: Sound beams are narrowed at the level of the focal point enhancing lateral resolution. Place the focal point at the depth level of interest on the ultrasound image. Can more than one focal point be set?

Answer 77

Yes, more than one focal point can be set that increases the area of resolution but decreases frame rate because of the time involved in focusing the image.
But cardiac imaging usually uses no more than one focal point.

Question 78

Harmonics: Value?

Answer 78

When ultrasound in transmitted at one frequency and returned at twice the transmitted frequency, it is called tissue harmonic imaging. This imaging mode is used to enhance the definition of endocardial borders and reduces the generation of artifacts, especially in patients with poor acoustic windows.

Question 79

Where are harmonic frequencies created?

Answer 79

Within the thorax, and not at the chest wall where many annoying artifacts originate, and turning harmonics on alleviates many of these imaging artifacts. It also enhances contrast resolution of the ultrasound image.

This simple control is easy to turn on and off; on some machines it is a push of a button, on others it involves reducing the transmitting frequency. It is worth remembering to try it when image quality is poor.
Fig 2.91.

Question 80

Gray map:

Echoes returning from tissues are assign a shade of gray based upon their signal strength (amplitude). Different gray maps assigns more or less gray to an image. Maps with less gray lump a range of signal strengths together and assign one gray shade to that range resulting in an image with more contrast than an image that uses a gray map with a greater range of grays. This is usually a post processing button on the machine that allows adjustment of gray maps on a frozen or stored image. Value?

Answer 80

A different map may enhance a lesion that is difficult to detect with the preset gray map. A different gray map may also enhance the image quality in an animal that is difficult to scan.