Contrast Echo Flashcards
1
Q
Saline Contrast Echo
Intravenous injection of microbubbles to opacify the cardiac chambers or evaluate myocardial perfusion is called __________
A
contrast echocardiography
2
Q
Agitated saline contrast opacifies the _____ and is used for detection of _________based on the appearance of contrast in the left heart.
A
right heart
right to left intracardiac shunting
3
Q
Smaller microbubbles size _____ in diameter transverse the _______ vasculature, allowing left heart chamber and myocardial opacification.
A
1-5 micrometer
pulmonary
4
Q
1mm = micrometer [µm]
A
1000 [µm]
5
Q
What are the indications for the use of agitated saline for right heart opacification?
A
- TIA (transient ischemic attack) - usually resolve within 48 hrs
- CVA (cerebrovascular accident) - last longer than 48hrs and cause damage
- suspect septal defect (ASD/VSD)
6
Q
What is the contraindication for the use of agitated saline for right heart opacification?
A
pregnant women
7
Q
Use of _________ is not recommended in women who are pregnant
A
bacteriostatic saline
Bacteriostatic saline is a physiological saline solution containing the bacteriostatic agent benzyl alcohol as a 0.9% solution. It is used mostly for diluting and dissolving drugs for IV injection and as a flush for intravascular catheters. It also has local anesthetic properties.
8
Q
List 4 clinical applications for agitated saline
A
- right to left shunt
- left to right shunt (*negative contrast due to the pressure gradient - microbubbles won’t cross the shunt since the LA has higher pressure)
- PFO
- enhance Doppler signals of TR
- pulmonary ateriovenous malformation
*Arteriovenous malformations (AVMs) refer to arteries and veins with abnormal connections between them.
9
Q
_______ is standard for the diagnosis of PFO
A
saline contrast
*Saline is a mixture of salt and water. A normal saline solution is called normal because its salt concentration is similar to tears, blood and other body fluids (0.9% saline). It is also called isotonic solution. A homemade saline solution can be used to: rinse the nasal passages (nasal irrigation)
note: saline contain small amount of alcohol to mitigate any pain
10
Q
Supplies used for bubble study:
A
- 10cc syringes x 2
- 9.5 mL saline
- 0.5 mL room air
- 3-way stopcock
- IV access
11
Q
The agitated saline bubbles go through your IV, right side of the heart and travel to and through the vessels within your lungs. Normally the lungs will filter out all of the saline bubbles or allow for very slow passage of the bubbles to the left side of the heart.
T or F ?
A
T
12
Q
What is PAVM?
A
Pulmonary arteriovenous malformations (PAVM) are rare pulmonary vascular anomalies. Although most patients are asymptomatic, PAVMs can cause dyspnoea from right-to-left shunt. Because of paradoxical emboli, various central nervous system complications have been described including stroke and brain abscess.
13
Q
If the patient has a PAVM, the agitated saline bubbles will appear in the ____ of the heart after ______ of the heart and the test would be considered positive for intrapulmonary (within the lung) shunting (blood moving through a vessel without a capillary be
A
left side
3-5 beats
14
Q
Microbubble characteristics
size:
A
1.1 - 8.0 micrometer or (2-8 micrometer)
*note: size of RBCs are 6-8 micrometer
15
Q
Microbubble characteristics
stability
A
3-10min depending on the rate of injection and equipment setting
16
Q
Microbubble characteristics
composition (2 types)
A
- outer shell (lipid membrane)
- contained gas (high-density perfluorocarbon)
17
Q
Microbubble characteristics
acoustic properties:
A
- Acoustic impedance mismatch between outer shell and contained gas should be sufficient to enhance the reflected signal
- Resonant frequency doubles from transmitted frequency but diminishes amplitude
18
Q
Contrast media for left heart opacification and myocardial perfusion:
appropriate rate and concentration
A
- Bolus: 10L/kg within 30-60 seconds followed by 10 mL saline flush
- Diluted Bolus: contrast diluted with saline
- Continuous infusion: _1.3 mL of contrast added to 50 mL of preservative free salin_e at the rate of 4.0 mL/min
*Bolus: A single dose of a drug or other substance given over a short period of time. It is usually given by infusion or injection into a blood vessel. It may also be given by mouth.
19
Q
Contrast media for left heart opacification and myocardial perfusion:
Continuous image acquisition at high intensity levels has a tendency to _______________
A
destroy contrast agent
20
Q
Sequential or intermittent imaging is used to spare the contrast agent.
T or F?
A
T
21
Q
Contrast imaging can be gated or triggered to the ECG to allow time between imaging for restitution of the contrast.
T or F?
A
T
22
Q
Appropriate equipment settings should be maintained to avoid destroying the contrast enhancement. Use vendor supplied presets.
T or F ?
A
T
23
Q
For normal 2-D imaging the MI is set at ______
A
0.9- 1.4
24
Q
For contrast imaging the MI is at a lower setting between _________to avoid bursting of bubble for longevity of visualization.
A
0.4 and 0.6
25
_Appropriate Equipment Settings:_
TDR frequency with optimal ______ should be selected.
penetration
26
_Appropriate Equipment Settings:_
Harmonic imaging should be selected with appropriate dynamic range, receiver filter, transmit frequency spectrum.
T or F ?
T
27
_Appropriate Equipment Settings:_
Focal zone should be placed in the \_\_\_\_\_\_\_
far field
28
_Appropriate Equipment Settings:_
Gain should be minimized in _____ (use \_\_\_\_)
the near field
TGCs
29
Indications for Use of Microbubble contrast:
* Predominate use is for **opacification of left ventricular cavity to enhance wall border detection**
* Used when standard transthoracic 2-D imaging is non-diagnostic
* May be used to **enhance a weak aortic stenosis jet** or **pulmonary vein flow** (used less often)
30
Contraindications for Use of Microbubble contrast:
* Known or suspected right to left shunts
* Pulmonary hypertension
* Pregnant or nursing mothers
* Hypersensitivity to perflutren
\*note: **Perflutren** is an ultrasound contrast agent that is used to improve the quality of an echocardiogram (ultrasound of the heart). Perflutren works by changing the way ultrasound waves travel within your heart. This helps the ultrasound portray a sharper image of your heart.
Perflutren is used to allow certain segments of the heart to be seen more clearly on an echocardiogram.
31
Currently, echocardiographic contrast agents are indicated for LV opacification and endocardial border definition in patients with technically suboptimal studies.
The two FDA approved agents in the United States are _____ **(perflutren protein type A microsphere) and ______ (perflutren lipid microsphere)**.
**Optison**
**Definity**
32
\_\_\_\_\_\_\_\_\_ (sulfur hexafluoride lipid-type A microspheres) is an ultrasound ***contrast agent*** indicated for use: in ***echocardiography*** to opacify the left ventricular chamber and to improve the delineation of the myocardium
***LUMASON***
33
Color Doppler is typically ______ by contrast injection.
degraded
34
There are a variety of ways microbubbles interact with the ultrasound beam including direct reflection of the fundamental frequency and resonance with creation of harmonic frequencies.
The maximum reflected frequency is dependent on the ______ of the bubble. The amplitude of the reflected frequency ______ as the bubble diameter decreases.
diameter
decreases
34
There are a variety of ways microbubbles interact with the ultrasound beam including direct reflection of the fundamental frequency and resonance with creation of harmonic frequencies.
The maximum reflected frequency is dependent on the ______ of the bubble. The amplitude of the reflected frequency ______ as the bubble diameter decreases.
diameter
decreases
35
\*Key considerations that have guided the design of UEAs are that they must be safe, able to transit the _________ and _________ microcirculation unimpeded, and sufficiently stable after intravenous injection to reach the left ventricular cavity and he myocardium to produce strong acoustic signals.
pulmonary
systemic
36
What are the applications of Contrast Echocardiography?
* **Endocardial border definitions**
* **Myocardial perfusions**
* **Doppler signal enhancement**
* **Definition of cardiac mass**
37
**Informed consent** should be obtained prior to contrast injection (see manufacturer warnings) & Patient should be monitored for reactions for **30 minutes** post injection.
T or F ?
T
38
\*You should never inject an ultrasound contrast agent into a PIC line.
T or F ?
T
39
\*When performing a contrast echo with an ultrasound contrast agent, you should select a transducer with the highest frequency possible.
T
40
**\*List 4 applications for the use of ultrasound contrast agents.**
* **Endocardial border definitions**
* **Myocardial perfusions**
* **Doppler signal enhancement**
* **Definition of cardiac mass**
41
**\*When performing a contrast echo with an ultrasound contrast agent, most manufacturers of ultrasound equipment recommend that the focal zone should be placed in the near field.**
**T or F ?**
F
\*focus should be placed in far field
42
**\*Agitated saline is utilized for right heart opacification in cases where the patient has experienced transient ischemic attack (TIA) or a cerebrovascular accident (CVA) to determine the source of embolus?**
**List 4 of the 5 clinical applications for agitated saline we discussed in class.**
* Right to left shunts
* Left to right shunt (negative contrast)
* PFO (Saline contrast is the standard for this diagnosis)
* Enhance Doppler signals of tricuspid regurgitation
* Pulmonary arteriovenous malformations
43
***\*Patient should be monitored for reactions for \_\_\_\_\_\_\_\_\_minutes post injection.***
30
44
***\*Agitated Saline _ Bubble study\_ is used for the detection of shunts such as PFO and ASD.***
***T or F ?***
T
45
***\*List 4 instrument settings to optimize left heart contrast images.***
* a decrease in power output (mechanical index of about **0.5**)
* a lower transducer frequency
* An _increase in overall gain and dynamic range_
* Focal depth at the mid or near-field of the image - some manufacturers recommend at the bottom of the screen
46
What is going to happen when microbubble density is too high?
cause attenuation
excessive apical contrast results in shadowing of the rest of the ventricle.
47
What is going to happen with low microbubble density or high mechanical index?
results in a swirling appearance with inadequate LV opacification.
48
Left-sided contrast in contraindicated in patients with _______ or _______ to echo contrast
right to left or bidirectional shunts
hypersensitivity
49
Caution is needed (with blood pressure, arterial oxygen saturation, and ECG monitoring) in patients with ________ or \_\_\_\_\_\_\_\_.
pulmonary hypertension
unstable cardiopulmonary conditions
50
Assessment of myocardial perfusion by contrast echocardiography is not widely used for clinical diagnosis, although there is ongoing development of this approach.
T or F ?
T
51
**\*At higher acoustic pressures, (MI generally \> 0.5) exaggerated microbubble oscillation produces microbubble destruction, which is termed \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.**
inertial cavitation
52
**\*Agitated saline contrast opacifies the right heart and is used for detection of _________ to ________ intracardiac shunting based on the appearance of contrast in the left heart.**
right
left
53
**\*List 4 contraindications to the use of ultrasound contrast agents.**
* Known or suspected right to left shunts
* Pulmonary hypertension
* Pregnant or nursing mothers
* Hypersensitivity to perflutren
54
**\*For Contrast Echos utilizing Definity or Optison, the focal zone should be placed in the ________ field.**
far
55
***\*Right heart contrast typically is used to enhance LV endocardial border detection when transthoracic image quality is suboptimal.***
***T or F ?***
F
\*Left heart contrast, not righ
56
**\*The IV for contrast insertion should be placed in the dominant arm if possible.**
**T or F ?**
F
\*IV placement should be in non-dependent right arm if possible
57
***\*When imaging at low acoustic power, the degree of signal enhancement is governed by the magnitude of oscillation, also called \_\_\_\_\_\_***
***stable cavitation.***
58
***\*When using an ultrasound contrast agent, caution is needed (with blood pressure, arterial oxygen saturation, and ECG monitoring) in patients with pulmonary hypertension or unstable cardiopulmonary conditions.***
***T or F ?***
T
59
***\*Inappropriate settings on the ultrasound system will not cause contrast destruction.***
***T or F ?***
F
inappropriate settings will cause contrast destruction
60
***\*Ultrasound Contrast agents may be used to enhance a weak aortic stenosis jet.***
***T or F ?***
T
61
***\*Informed consent should be obtained prior to contrast injection (see manufacturer warnings).***
***T or F ?***
T
62
***\*When performing a contrast echo with an ultrasound contrast agent, the MI should be set at \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.***
0.4 - 0.6
63
***\*Smaller microbubbles (1-5 ųm diameter) transverse the pulmonary vasculature, allowing left heart chamber and myocardial opacification.***
***1 MM = __________ ųm***
1000
64
***\*For normal 2-D imaging the MI is set at 0.9 – 1.4. However, for contrast imaging the MI is at a lower setting between _________ and ________ avoid bursting of bubble for longevity of visualization.***
0. 4
0. 6
65
***\*Agitated saline is the typical choice for the detection of a patent foramina ovale.***
***T or F ?***
T
66
Inertial cavitation activity produces very strong broadband ultrasound signals by a variety of mechanisms.
The most important of which is the abrupt release of free gas microbubbles from the confines of their shell, which can then undergo nondamped exaggerated oscillation.
T or F ?
T
67
_Micro Bubble Components_
composed of:
albumin
galactose
lipids polymers
\*the more elasticity, the more acoustic energy it can withstand before bursting
68
_Microbubble Component (core)_
composed of:
* **air**
* **heavy gases** - perfluocarbon or nitrogen (less water soluble and last longer in circulation, size: 1-4 micrometer smaller than RBCs)
69
7 indications for bubble study
1. **detection of shunts (PFO, ASD)**
2. detection of **persistent left SVC:** Persistent left superior vena cava (PLSVC) is **a rare vascular anomaly that begins at the junction of the left subclavian and internal jugular veins, passes through the left side of the mediastinum adjacent to the arcus aorta**. It mostly drains into the right atrium via the coronary sinus (CS)
3. **intensifying TR** signal when you have difficulty estimating RV systolic pressure
4. **delineating right heart borders and masses** (includes RV wall thickness)
5. improving imaging of the _pulmonary trunk and arteries,_ especially when looking for thrombi
6. during **echo-guided pericardiocentesis**
7. **central venous line control** after insertion
70
advantage of contrast
* provide real time evaluation of the heart
* safer than other contrast agents and invasive cardiac testing
* more cost effective than other imaging
* portable procedure even with contrast
71
disadvantages of contrast:
* decreased time in circulation
* produces heart with increased frequency
* burst with low frequencies and high MI
72
What will contrast improve?
* **endocardial border definitio**n
* enhance wall motion for stress testing
* provide a border for tracing EF
* WMA
apical hypertrophy
* **enhance other pathology**
* thrombus
* TEE LAA thrombus
* aortic dissection
* Doppler signals
73
_Patient Monitoring_
What are the waring signs after the injection of contrast agent?
* flushing
* discomfort/headache
* flank pain: Flank pain **affects the area on either side of the lower back, between the pelvis and the ribs**
* **itchiness**
* **SOB**
74
What impact contrast imaging quality?
* difficult unenhanced image quality
* IV placement
* injection technique
* equipment settings
75
IV placement tips:
* In non-dependent right arm if possible
* as proximal as possible
* injection site as close to hub as possible
* use an existing IV
* sonographers **MUST HAVE RN** shut off any meds
* sonographers should **NEVER** inject into an central or PIC line
* ensure there is an injection site close to hub
76
Proper injection technique:
* Inject **0.3-0.5 mL** dose of contrast depending on patient and dilution
* a slow saline flush should follow even with diluted contrast - **3mL over 10sec**
* if the _EF is low and/or apical WMA_ - a more vigorous flush or additional contrast may be needed to completely fill apex
* if the _patient is large_, you may need more contrast
77
Steps to eliminate Swirling
* MI too high - check the preset
* administration rate should be increased
* flush faster with saline
* administer more contrast
* will occur with low flow states in LV
* raise arm to enhance flow contrast
* squeeze arm to enhance venous flow
78
Contrast equipment settings:
* set up and utilize a contrast preset
* this is a starting point sine all the patients are different
* utilize Harmonics
* decrease MI - 0.1-0.6
* increase receiver gains - TGCs & 2D gain
* optimize dynamic range/compression
* lace focal zone at MV level
79
Steps for contrast study:
* explain need to use contrast to patient
* determine O2 saturation \>90%
identify suitable injection site
* use sterile technique
* if injection into existing IV, check for any meds that may be running (NEVER use central or PIC line)
* if meds running call for RN to D/C meds
* communicate with scanning sonographer as when to inject, flush, speed of injection, or additional contrast
80
Contrast Troubleshooting Tips:
**apex is not filling properly -** decrease MI and
**administer more contrast fastercontrast is dim -** increase receiver gain & inject more contrast
**attenuation**
* inject slower
* use less contrast
**poor delineation**
* decrease overall gain
* adjust compression
81
Why is contrast utilization so important?
* chemotherapy: \>5% decrease
* CRT indication: ≤35%
* ICD indication: ≥35%
82
673. All of the following symptoms would indicate an anaphylactic reaction to an echocardiography contrast agent except:
1. rash
2. swelling
3. acute onset HTN
4. hypotension
3. acute onset HTN
83
674. which of the following is most likely to induce an anaphylactic shock?
1. a slow infusion of contrast
2. no administration of contrast
3. contrast - push administration of agitate saline bubbles
4. slow administration of agitated saline bubbles
5. a bolus administration of contrast
5. a bolus administration of contrast
\*note: bolus - a single dose of a drug or other medicinal preparation given all at once.
infusion - the slow injection of a substance into a vein or tissue.
84
675. When do most reactions to contrast occur relative to time of administration?
1. within 120-180 min
2. within 90-120 min
3. within 60-90 min
4. within 30-60 min
5. within the first 30 min
5. within the first 30 min
\*note: Common side effects of Definity include:
* injection site reactions,
* back and chest pain,
* headache,
* dizziness,
* nausea,
* flushing,
* fatigue,
* fever,
* [hot flashes](https://www.rxlist.com/script/main/art.asp?articlekey=7322),
* [fainting](https://www.rxlist.com/script/main/art.asp?articlekey=7661),
* fast or slow heart rate,
* [palpitations](https://www.rxlist.com/script/main/art.asp?articlekey=4741),
* high or [low blood pressure](https://www.rxlist.com/script/main/art.asp?articlekey=7670),
* [indigestion](https://www.medicinenet.com/dyspepsia/article.htm),
* [dry mouth](https://www.rxlist.com/script/main/art.asp?articlekey=24997),
* [toothache](https://www.rxlist.com/script/main/art.asp?articlekey=25128),
* abdominal pain,
* diarrhea,
* [vomiting](https://www.medicinenet.com/vomiting/symptoms.htm),
* [joint pain](https://www.medicinenet.com/joint_pain/symptoms.htm),
* leg cramps,
* spinning sensation ([vertigo](https://www.rxlist.com/script/main/art.asp?articlekey=6129)),
* numbness and tingling,
* cough,
* [sore throat](https://www.rxlist.com/script/main/art.asp?articlekey=40399),
* runny or [stuffy nose](https://www.rxlist.com/script/main/art.asp?articlekey=97621),
* shortness of breath,
* itching,
* rash,
* hives,
* increased sweating, and
* dry skin.
85
commercially available second-generation US contrast agent
86
In the vivo stability of microbubbles has been achieved by two straategies. Encapusulation of the microbubbles using ______ (arrange in a monolayer) or ____ has been used to reduce outward diffusion of the gas core and to reduce microbubble \_\_\_\_\_\_, which allows for the production of stable yet small microbubbles.
lipid surfactant
albumin shells
surface tension
87
MCE stands for?
myocardial contrast echocardiography
88
echo can be used serially (all the time) to assess cardiac function because it uses no ______ and is easily accessible, \_\_\_\_\_, and relatively ______ compared with other imaging techniques.
ionizing radiation
portable
inexpensive
89
In multicenter studies, the administration of UAEs during echo improved the identification of _____ when using ____ as a gold standard.
WMA
MRI
90
The currently available UEAs in the US are:
optison
lumason
definity
91
Thrombi are completely ______ and demonstrate no contrast
avascular
92
masses that are brighter than the surrounding myocardium (hyperenhanced) suggests \_\_\_\_\_\_
highly vascular or malignant tumor
93
myxomas, lipomas, or fibromas have a poor blood supply and appear \_\_\_\_\_\_\_
hypoenhanced
94
Lumason, Optison and Definity are currently approved only for \_\_\_\_\_, but ____ is also approved for adult and pediatric liver and vesicular imaging.
LVO (left ventricular opacification)
Lumason
95
one of the most important things to avoid is excessive contrast in the LV cavity causing \_\_\_\_\_.
acoustic shadowing
96
97
For LV function, inadequate visualization of ________ has been used to define a study as “technically difficult” or “suboptimal”
2 or more endocardial borders
98
Imaging techniques have been modified to image microbubbles at _____ mechanical indices/MI ( \_\_\_\_\_)
using fundamental nonlinear imaging.
very low
\< 0.2
99
The ASE guidelines recommended changing the terminology of ultrasound contrast agents to ______ for the purpose of distinguishing UEAs from traditional iodinated or magnetic resonance agents.
ultrasound enhancing agents (UEAs)
100
When imaging at low acoustic power, the degree of signal enhancement is governed by the magnitude of oscillation, also called \_\_\_\_\_\_\_
stable cavitation
101
The MI defined as \_\_\_\_\_\_\_\_\_\_\_\_, at which stable cavitation occurs, is less than ______ for most agents.
the peak negative acoustic pressure / the square root of the transmit frequency
0.25
102
At higher acoustic pressure (MI \> 0.5), exaggerated microbubble oscillation produces microbubble destruction, which is termed \_\_\_\_\_.
inertial cavitation
103
The success of contrast imaging depends on optimizing the \_\_\_\_, \_\_\_\_\_, and _____ for imaging, as well as controlling the contrast infusion rate or bolus size so as to obtain myocardial contrast enhancement without shadowing in the LV cavity
gain
TGC
MI
104
6-7micro m
105
attenuation
106
5 mL
10 sec
107
Current guidelines recommend ____ imaging with ____ nonlinear imaging for optimal LVO and endocardial border resolution.
very low MI
fundamental
