Week 3 - US Flashcards
U/S
Provides diagnoatic information by measuring reflections of focussed, high frequency sound waves from internal tissues
Images made up of a mosaic white and grey dots. Each dot represents an echo of a structure in a patient
Performed in real time
Sonographer
Trained and qualified in US
Records representation images for radiologist to report on
Transducer (probe)
Houses the piezoelectric crystal which has a dual function as transmitter of pulses and receiver of echoes
Converts electrical energy into mechanical energy (OUT)
Converts mechanical energy into electrical energy (IN)
Attenuation
Meaning reduction in intensity of the energy
Echogenicity
how bright the tissue or structure is - how intense the echoes are
Echotexture
Pattern of echoes
Anechoic
describe an area that has no echoes - appears black on the image (clear fluid, urine, blood, cysts)
Hypoechoic
Echo intensity is low - appears grey but echoes present
Soft tissue, tendon
Hyperechoic/ Echogenic
Brighter on the screen. White.
Bone, calcification, renal/gall stones
Homogenous
Very even pattern
Heterogeneous
Mixed pattern
US indications - Podiatrist
Tendon dysfunction
Plantar fascitis
Ligament injury
Soft tissue massess/foreign bodies
Morton neuroma
Tarsal tunnel syndrome
Joint effusion/synovitis
US Advantages
No ionising radition
Quick and cost effective
well tolerated by patients
Real time
Good if pregnant
US Disadvantages
Many areas not suitable to image US: bone, lungs, abdominal structures converted by bowel
US 2 effects on tissue
Thermal
Mechanical
