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Purpose of ultrasound
With regards to the musculoskeletal system it helps diagnose partial tendon tears, soft-tissue masses (e.g., tumors, hematomas), pockets of fluid, muscle development or activation.first imaging modality for accurate soft tissue diagnosis TERM 2
What is ultrasound?
DEFINITION 2 Diagnostic sonography (ultrasonography)An imaging technique for visualizing internal body structures including:TendonsMusclesJointsVesselsInternal organs TERM 3
Principles of ultrasound
DEFINITION 3 Medical diagnostic ultrasonography uses ultrasound (high- frequency sound waves) to visualize soft tissue structures in the body in real time & blood flowing in tissues TERM 4
Quality of the images obtained using
ultrasound is highly dependent on what?
DEFINITION 4 on the skill of the person (ultrasonographer) performing the exam. TERM 5
Unique attributes of US
DEFINITION 5 Diagnostic US is dynamic imagingApplied to the patient in real time.Can be part of a clinical exam.
Significance of frequency and ability to see
structures
Higher frequency is better suited for viewing superficial structures. This is due to scatterIf you wanna see deeper structures, have to turn frequency down TERM 7
Interaction of ultrasound and the body
DEFINITION 7 can be absorbed, reflected, and diffused in body tissue due to refraction and scattering TERM 8
How is ultrasound limited?
DEFINITION 8 limited by its inability to image through air (lungs, bowel loops) or bone and fat. TERM 9
How is ultrasound described?
DEFINITION 9 not described in orthogonal terms, but as longitudinal or transverse images of the scanned structure TERM 10
ultrasonography equipment
DEFINITION 10 pulsertransducerscan converter and monitor
Therapeutic US vs diagnostic US
Therapeutic US causes a rise in tissue temperature, but the energy level of diagnostic US is low and does not raise tissue temperature TERM 17
How is the US image obtained?
DEFINITION 17 Transducer is applied directly to the skin with an intervening layer of gelThe ultrasonographer locates structures by palpation before and during the exam through the transducerThe ultrasonographer continuously monitors and changes the image during the examMusculoskeletal tests can be performed during the exam TERM 18
Scanning planes in US
DEFINITION 18 CT/MR: use orthogonal planesUltrasound is described relative to the structure being examinedLongitudinal sonogram = aligned with the long aligned with the long axis of a muscleTransverse sonogram = cross-sectional view of the muscle TERM 19
Significance of signal
intensities
DEFINITION 19 Tissues do not have set characteristic tissue intensities.The intensity of reflection from the tissues depends on the nature of the tissue interface, the angle of the beam, and the type of tissue TERM 20
Echogenicity
DEFINITION 20 describes the tissues ability to return an echo or signal during the US exam echo, or signal, during the US exam
hyperechoic (bright)
Tissues or interfaces that reflect much energy TERM 22
hypoechoic (dark)
DEFINITION 22 Tissues or interfaces that reflect little energy TERM 23
anechoic
DEFINITION 23 No reflection TERM 24
example of hypoechoic
DEFINITION 24 BONE TERM 25
example of hyperechoic
DEFINITION 25 bone-soft tissue interfacetendonsligaments
Disadvantages of US
Operator dependent; requires refined technical skill to acquire images US does not penetrate bone so structures deep to bone (intraarticular) are not seen US does not cross air interfaces, problematic to image structures obscured by air in the lungs or gas in the intestines Very heavy patients are not imaged well due to loss of acoustic energy and correct focal length TERM 32
Doppler Ultrasonography
DEFINITION 32 Slightly different than standard Diagnostic US It is a non-invasive test to evaluate blood flow in major arteries, veins, and the brain. US relies on high frequency sound waves to make cross sectional images in many planes US is safer, cheaper, takes less time to do than arteriography and venography. It does NOT use ionizing radiation. TERM 33
Angiography purpose
DEFINITION 33 a common procedure that helps the medical team evaluate and diagnose a client's conditionprovides valuable information for prognosis and treatment interventionThe primary purpose of this procedure is to examine blood vessels throughout the body or it may be used to guide intervention e.g., stent placement. TERM 34
what is angiography?
DEFINITION 34 A catheter and a contrast material are often used in conjunction with x-rays, CT scan, or MRI. TERM 35
PET scan purpose
DEFINITION 35 Used to detect non-perfusing (poor blood flow) areas of the heart or to evaluate the brain in cases of undetermined dementia, stroke, seizures, memory disorders, or suspected tumors.
What is a PET scan
positrons emitting from radioactive substance are captured.The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule.
