Ultrasound Basics Quiz

Ultrasound Basics

• Sound is a vibration that travels through a medium, like air.
• Ultrasound is sound with a frequency higher than humans can hear.
• Normal human hearing range is from 12 Hz to 20 kHz.
• Ultrasound uses frequencies typically between 2 and 20 MHz.

Tissue Interaction

• Reflection: Sound waves bounce off tissue boundaries with different densities.
• Absorption: Some sound waves are absorbed by tissue, reducing reflected echoes.
• Refraction: Sound waves change direction when passing through tissues with varying speeds.

Basic Terminology

• Echogenicity: The ability of a tissue to reflect sound waves, showing up as brightness on the image.
• Hyperechoic: Bright, like bone or fat.
• Isoechoic: Similar brightness to surrounding tissues.
• Hypoechoic: Darker than surrounding tissues, like muscle.
• Anechoic: Black, like fluid-filled structures (e.g., cysts, bladder).

Ultrasound Components

• Transducer: The probe, containing piezoelectric crystals that send and receive ultrasound waves.
• Cable: Carries electrical signals to and from the probe.

Types of Ultrasound Probes

• Linear probe: High frequency (5-15 MHz), used for superficial structures (e.g., thyroid, blood vessels).
• Curvilinear probe: Lower frequency (2-5 MHz), used for imaging larger body areas like the abdomen and pelvis.
• Phased array probe: Narrow beam, used for imaging the heart and structures between ribs.
• Endocavitary probe: Specialized probe used for transvaginal or transrectal imaging.

Basic Ultrasound Modes

• B-mode (Brightness Mode): Creates a two-dimensional grayscale image based on tissue density.
• M-mode (Motion Mode): Displays the movement of structures over time, primarily used for cardiac imaging.
• Doppler Mode: Used to visualize blood flow.
  • Color Doppler: Shows the direction and velocity of blood flow.
  • Spectral Doppler: Provides a waveform representing blood flow velocity.
  • Power Doppler: Very sensitive to low-flow states, but doesn't show direction.

Doppler Ultrasound

• Doppler ultrasound measures the frequency change of reflected ultrasound waves to assess the speed and direction of moving objects, including blood flow.

Ultrasound Orientation

• Transverse section (TS): Shows the body in a horizontal plane.
• Longitudinal section (LS): Shows the body in a vertical plane.
• Image orientation reflects the patient's anatomy. Left side on the image=right side of the patient, and vice versa.

Ultrasound Artifacts

• Acoustic shadowing: Dark area behind a dense object (like gallstones).
• Posterior enhancement: Bright area behind a fluid-filled structure.
• Reverberation: Repeated echoes creating a comet-tail-like effect.

Abdominal Ultrasound

• Examines liver, kidneys, gallbladder, pancreas, and spleen.
• Reports typical appearances based on tissue echoes.

MSK Ultrasound

• Examines tendons muscles and joints for injuries.

Shoulder Ultrasound

• Evaluates shoulder anatomy and detects possible problems

Knee Ultrasound

• Examines knee anatomy and detects possible problems

Pelvic and Obstetrical Ultrasound

• Examines the uterus, ovaries, and bladder.
• Monitors fetal growth and development during pregnancy.

Cardiac Ultrasound

• Examines heart function and structure.

Small Part and Soft Tissue Ultrasound

• Examines thyroid, breast, scrotal and other soft tissue regions.

Thyroid Ultrasound

• Images the thyroid gland.

Ultrasound Advantages and Limitations

• Advantages: Safe (no ionizing radiation), real-time imaging, portable, relatively inexpensive.
• Limitations: Limited penetration (obese/gassy patients), operator-dependent, limited imaging behind bone or air-filled structures.

Ultrasound Therapy (or Physical Therapy Ultrasound)

• Used to promote tissue healing, pain reduction, and improved mobility.
• Uses high-frequency sound waves for deep heating or mechanical effects.

Ultrasound Therapy Equipment

• Continuous ultrasound: Constant waves to produce heat.
• Pulsed ultrasound: Pulsed waves produce non-thermal effects.

Ultrasound Application Techniques

• Coupling medium (gel) is used to transmit sound waves between the transducer and the skin.
• Direct contact.

Ultrasound Indications

• Muscle strains and sprains
• Tendonitis
• Joint stiffness
• Pain management

Ultrasound Contraindications

• Open wounds
• Metal implants (without proper assessment)
• Pregnancy (avoid abdomen/lower back)
• Eyes, heart, reproductive organs
• Malignant tumors

Ultrasound Safety Tips

• Test equipment before use.
• Use appropriate coupling gel.
• Move transducer continuously,
• Monitor patient comfort.
• Use lower intensities initially.