Clinical Applications of Ultrasound Lecture Flashcards
20/11/24
What are the benefits of ultrasound?
Based on non-ionising radiation
What are the risks of ultrasound?
Waves can heat the tissues slightly.
It can produce small pockets of gas in body fluids or tissues.
What is the thermal index?
An onscreen indication of the relative potential for a tissue temperature rise
What is the mechanical index?
An onscreen indication of the relative potential for ultrasound to induce an adverse bio effect by a non-thermal mechanism such as cavitation.
Which measures can be taken to minimise the risks of diagnostic ultrasound?
Only use when medically indicated, for the shortest exposure time possibe. Watch TI, MI and the clock.
What is ALARA?
‘As Low As Reasonably Achievable’ - making every reasonable effect to maintain exposures to ionising radiation as far below the dose limit as possible.
When may ultrasound be used?
Either to answer a specific diagnostic question or to guide performance of an invasive procedure
What is focused assessment with sonography for trauma? (FAST/eFAST)
A&E, patients admitted with blunt abdominal trauma, and US can be used to identify presence of free fluid in the peritoneal cavity - no attempt to visualise specific organ injuries.
What makes FAST different from eFAST?
FAST is just to detect free fluid in peritoneal, pericardial, and pleural spaces, while eFAST also adds an assessment to detect hemothorax or pneumothorax (collapsed lung).
What is echocardiography?
The use of ultrasound to examine the heart e.g. estimation of heart function by the left ventricular ejection fraction (LVEF).
What are other potential uses of ultrasound?
US guided joint aspiration
Cranial ultrasound
Breast ultrasound
Ultrasound guided biopsy
Antenatal screening
How is ultrasound used for lithotripsy?
Stones present in the urinary system are crushed into small sand like particles by the vibratory impulses generated by us shock waves, and the small particles can then be excreted in the urine.
