Ultrasound 3 Flashcards
What happens in the TEE procedure?
The entire procedure lasts 30 to 60 minutes.
Local anesthetics is used to numb the throat and suppress the gag reflex.
A mild sedative is injected intravenously to help patient stay calm.
ECG is usedto monitor patient’s heartbeat.
The probe and the catheter are guided through the mouth and down the throat.
The TEE is then taken in 10 to 15 minutes.
When the TEE is finished, the probe, IV and the ECG electrodes are removed.
A nurse will monitor the patient until the effect of the sedative wears off.
Compare: 2D Tee vs 3D Tee
The main difference between 2D TEE and 3D TEE lies in the level of detail and visual information they provide. While 2D TEE offers two-dimensional images, 3D TEE provides a more comprehensive three-dimensional representation of the heart.
Additionally, the 3D TEE procedure requires more advanced equipment and expertise to acquire and interpret the images accurately. It may also take longer to perform compared to a 2D TEE procedure.
How are blood velocities within the body measured?
Doppler Ultrasound is a non-invasive technique for measuring blood velocities within the body.
Briefly explain the Doppler effect while giving an example.
It relies on the Doppler Effect which is
the apparent change in the frequency of a wave due to relative motion between the wave source and the observer.
An example of the Doppler Effect can be observed with sound waves. Imagine standing on a sidewalk while a car passes by with its horn blaring. As the car approaches you, the sound waves are compressed, causing the pitch of the horn to be higher. However, as the car moves away from you, the sound waves are stretched, causing the pitch of the horn to be lower.
Ultrasound Doppler
The ultrasound Doppler is a medical imaging technique used to assess blood flow velocity and direction in the body. It utilizes the principle of the Doppler effect, which describes the change in frequency of sound waves when there is relative motion between the source of the waves and the observer.
What happens in the first doppler shift?
The first Doppler shift, also known as the Doppler frequency shift, occurs when there is a difference between the frequency of the transmitted ultrasound waves and the frequency of the waves reflected by moving blood cells or tissues.
This shift in frequency allows the ultrasound machine to detect the velocity and direction of blood flow. When blood cells move towards the ultrasound probe, the reflected waves have a higher frequency or pitch. Conversely, when blood cells move away from the probe, the reflected waves have a lower frequency or pitch.
What happens in the second doppler shift?
The second Doppler shift, also called the color Doppler shift, is used to display blood flow information in real-time. It combines both the first Doppler shift and the B-mode ultrasound imaging to create a color-coded representation of blood flow.
With the second Doppler shift, different colors are assigned to represent blood flow direction and velocity. For example, red may indicate blood flow towards the probe, while blue indicates blood flow away from the probe. The intensity of the color can also correspond to the speed of the blood flow.
What is a laser doppler imaging?
Laser Doppler Imaging (LDI) is a non-invasive imaging technique used to measure blood flow in tissues. It works by illuminating the tissue with a laser beam and analyzing the frequency shift of the scattered light caused by the motion of red blood cells. This information is then used to generate a color-coded image that represents the blood perfusion in the tissue, allowing for the assessment of microcirculation and vascular abnormalities.
List some physiological effects of ultrasound
Ultrasound is energy and is absorbed by tissue, the absorption depends on the property of tissue
This absorption can cause heating
Diagnostic imaging : uses pulse intensities ~ 0.01 W/cm2.
No harmful effects have been reported.
Physiotherapy uses ~1 W/cm2 as a source of deep heating.
Intensities higher than 1 W/cm2 are sometimes used to destroy living tissue.
Shock wave lithotripsy is used to…
break up bladder or kidney stones.
