Ultrasonography and Bone Scans (finished) Flashcards
What is an ultrasound/ultrasonography?
- Ultrasound is the name given to high-frequency sound. The ultrasound pulse travels through the body and echoes off the internal organs. In ultrasonography, a signal generator is combined with a transducer
How does the ultrasound work?
- Piezoelectric crystals in the signal generator convert electricity into high-frequency sound waves, which are sent into tissues.
- The tissues scatter, reflect, and absorb the sound waves to various degrees. The sound waves that are reflected back (echoes) are converted into electric signals. A computer analyses the signals and displays the information on a screen.
- Although ultrasound travels through soft tissue and fluids, it bounces back off denser surfaces. Ultrasound will travel through blood, for example in the heart chamber, but much of it will echo (bounce back) when hitting a heart valve.
- Stronger echoes appear as brighter dots on the screen
- Images are described as hypo or hyper-echoic
What’s the difference between Diagnostic Ultrasound and Therapeutic Ultrasound?
- Diagnostic ultrasound is: “the use of ultrasound to obtain images for medical diagnostic purposes, employing frequencies ranging from 1.6 to 10 MHz.
- Therapeutic ultrasound is: “high-intensity ultrasound causing coagulation necrosis of tissue, used in treatment of some benign tumours, such as uterine leiomyoma”
What is ultrasound used for?
- Diagnosis or treatment (therapeutic procedures)
- Guidance during procedures that require intervention, such as biopsies and cortisone
Describe the following example of Medical Sonography:
“Anestesiology”
When injecting needles with anaesthesia solutions near nerves
Describe the following example of Medical Sonography:
“Cardiology”
Images of the cardiovascular system, echocardiograms can accurately assess the speed of blood flow and cardiac tissue at specific points using pulses or continuous wave Doppler ultrasound
How is ultrasound used in emergency medicine?
FAST (Focused Assessment with Sonography for Trauma) for assessing trauma, pericardial tamponade (fluid builds up in the sac in which the heart is enclosed; the pericardium) or hemoperitoneum (blood in the peritoneal cavity)
What is the following used for:
“Newborn Infants (neonatology)”
Abnormalities in the brain, hydrocephalus (placed over fontanelle)
What is Obstetric Ultrasonography used for?
Ultrasound is used to create images of the foetus or embryo in the uterus.
What is musculoskeletal sonography used for?
This can be used to examine ligaments, bone surfaces, soft tissue masses, nerves, muscles and tendons.
Does fluid show up black or white in an ultrasound?
Black
What are some limitations of ultrasound imaging of the musculoskeletal system?
- Ultrasound has difficulty penetrating bone and therefore can only see the outer surface of bony structures and not what lies within.
- Ultrasound has not proven useful in detecting whiplash injuries or other causes of back pain.
List some examples of how ultrasound can be used for therapy.
- Bringing agitation or heat to a targeted area in the body
- Used by dentists to clean teeth
- Used in cancer treatment, physical therapy and occupational therapy
- Mixed results in musculoskeletal therapies
- Focused Ultrasound Surgery (FUS) or High Intensity Focused Ultrasound (HIFU) can generate localised heat to treat tumours and cysts
- Lithotripsy can be used to break up kidney stones
- Cataracts can be treated via phacoemulsification
- Low-intensity ultrasound may help stimulate bone-growth, as well as helping drugs pass the blood-brain barrier
What are some benefits of using ultrasound?
- Most ultrasound scanning is non-invasive and is usually painless
- Is widely available, easy-to-use and less expensive than other imaging methods
- Uses no ionising radiation
- Gives a clear picture of soft tissues that do not show up well on x-ray images
- Causes no health problems and may be repeated as often as necessary
- Provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and needle aspiration
- Unlike MRI, not affected by pacemakers, ferromagnetic implants or fragments within the body. Also an excellent alternative to MRI for claustrophobic patients
- May actually have advantages over MRI in seeing tendon structure, which is better appreciated by ultrasound than MRI
Are there any risks associated with using ultrasound imaging?
For standard diagnostic ultrasound, there are no known harmful effects on humans.
What sort of image is this?
What’s the diagnosis?
- Ultrasound
- Diagnosis: Colateral ligament tear
Find the following structures in the ultrasound below
- Biceps tendon
- Bicipital groove
- Humerus
- Fluid within biceps tendon sheath
What is the arrow pointing to?
Haematoma (can also be visualised in x-ray below)
What is the arrow pointing to?
Full-thickness subscapularis tendon tear with tendon retraction (short arrow)
What is the arrow pointing to?
Separation of the linea alba leading to herniation of intestinal region.
What are the arrows pointing to?
Tear through Vastus Medialis
