Introduction to Ultrasound Imaging

What is the range of frequencies used in diagnostic medical ultrasound?

2 – 15 MHz

What is the velocity of a sound wave through soft tissue?

1540 m/s

What is the frequency of a 7.5 MHz transducer?

7,500,000 Hz

What is the wavelength of a sound wave with a frequency of 3MHz?

0.51 mm Signup and view all the answers

What is the relationship between wavelength, frequency, and velocity of a sound wave?

c = λ × f Signup and view all the answers

What is the unit of measurement for the strength of a sound wave?

Decibels (dB) Signup and view all the answers

What is the principle employed by the transducer to generate sound waves and detect echo signals?

Piezoelectric effect Signup and view all the answers

What is the result of the Returning echoes on the ultrasound screen?

The brightness of the dots is proportional to the strength of the returning echoes Signup and view all the answers

What is the term used to describe an area that contains no echoes on the ultrasound image?

Anechoic Signup and view all the answers

What is the formula used to calculate the wavelength of ultrasound waves?

c = f.λ Signup and view all the answers

What is the term used to describe an area that contains only a few echoes on the ultrasound image?

Hypoechoic Signup and view all the answers

What is the role of the transducer in ultrasound imaging?

Both a transmitter and a receiver of ultrasound waves Signup and view all the answers

What is the frequency range used in Obstetrics and Gynaecology ultrasound applications?

2.5-5 MHz Signup and view all the answers

What is the purpose of the analogue to digital converter in the ultrasound system?

To convert the analogue signal to digital signal Signup and view all the answers

In which mode of ultrasound display is the echo plotted on the screen as a function of depth?

A-Mode Signup and view all the answers

What is the frequency range used in paediatric brain ultrasound applications?

6-7 MHz Signup and view all the answers

What is the purpose of the image memory in the ultrasound system?

To store the image as digits and pixels Signup and view all the answers

What is the frequency range used in thyroid and scrotum ultrasound applications?

10-14 MHz Signup and view all the answers

What does the display of echoes on a TV monitor show?

Different shades of grey with varying intensity levels Signup and view all the answers

What is emphasized in M-mode display?

The movement of interfaces, including rate, amplitude, and pattern of motion Signup and view all the answers

What is measured using M-mode display?

The movement of the aorta, left atrium, right ventricle, and valves Signup and view all the answers

What is combined with M-mode in Colour M-mode imaging?

Colour Doppler information Signup and view all the answers

What is displayed in conjunction with the corresponding segment of the cardiac cycle in Colour M-mode imaging?

The flow data and M-mode pattern Signup and view all the answers

What modality does Doppler ultrasound combine with to study blood vessels and blood flow?

Various modalities Signup and view all the answers

What is a necessary understanding for a sonographer to have in order to perform and interpret a Doppler examination?

All of the above Signup and view all the answers

What type of Doppler modulation is associated with slow flow velocity?

Power Doppler Signup and view all the answers

What is a limitation of ultrasound imaging?

Unable to penetrate calcific bone and air Signup and view all the answers

What is a potential biological effect of high-intensity pulsed wave ultrasound?

Cavitation and subsequent cell damage Signup and view all the answers

What is an advantage of ultrasound imaging?

It is a non-invasive and cost-effective modality Signup and view all the answers

What is the primary media used for image recording in ultrasound?