Ultrasound or ultrasonography is a medical imaging ...



Ultrasound or ultrasonography is a medical imaging technique that uses high frequency sound waves and their echoes. The technique is similar to the echolocation used by bats, whales and dolphins, as well as SONAR used by submarines.

In ultrasound, the following events happen:

1. The ultrasound machine transmits high-frequency (1 to 5 megahertz) sound pulses into your body using a probe.

2. The sound waves travel into your body and hit a boundary between tissues (e.g. between fluid and soft tissue, soft tissue and bone).

3. Some of the sound waves get reflected back to the probe, while some travel on further until they reach another boundary and get reflected.

4. The reflected waves are picked up by the probe and relayed to the machine.

5. The machine calculates the distance from the probe to the tissue or organ (boundaries) using the speed of sound in tissue (on average 1,540 m/s) and the time of each echo's return (usually of the order of millionths of a second).

6. The machine displays the distances and intensities of the echoes on the screen, forming a two dimensional image like the one shown below.

In a typical ultrasound, millions of pulses and echoes are sent and received each second. The probe can be moved along the surface of the body and angled to obtain various views.

A basic ultrasound machine has the following parts:

• Transducer probe - probe that sends and receives the sound waves

• Central processing unit (CPU) - computer that does all of the calculations and contains the electrical power supplies for itself and the transducer probe

• Transducer pulse controls - changes the amplitude, frequency and duration of the pulses emitted from the transducer probe

• Display - displays the image from the ultrasound data processed by the CPU

• Keyboard/cursor - inputs data and takes measurements from the display

• Disk storage device (hard, flash, CD) - stores the acquired images

• Printer - prints the image from the displayed data

The ultrasound that we have described so far presents a two-dimensional image, or "slice," of a three-dimensional object (fetus, organ). Two other types of ultrasound are currently in use, 3-D ultrasound imaging and Doppler ultrasound.

GLOSSARY:

similar – (like, comparable) - podobny

bats – (small animals like mice with wings that fly at night) - nietoperze

whales – (very large sea mammals that breathe air through holes at the top of their heads) - wieloryby

submarines – (ships that can travel underwater) - łodzie podwodne

transmit – (pass on, transfer) - przekazywać, przesyłać

probe – (a long, thin tool used by doctors to examine inside someone) – sonda, głowica

sound waves – fale dźwiękowe

boundary – (border, barrier) - granica

fluid – (~liquid) - płyn

soft tissue – tkanka miękka

bone – (osseous matter) - kość

relay to – (send, transmit) - przekazywać do

speed of sound – prędkość dzwięku

display (v.) (show, demonstrate) - wyświetlać

screen – (monitor, display) - ekran

two dimensional – (2D) dwuwymiarowy

receive – (accept, collect, get) - otrzymać, odebrać

surface – (top Or external part of sth.) - powierzchnia

angle (v) – ustawiać pod kątem

obtain – (get, acquire) - uzyskać

central processing unit (CPU) – centralna jednostka obliczeniowa, procesor

contain – (include, hold) - zawierać

electrical power supplies – zasilanie prądem elektrycznym, źródło prądu

duration – (period, term) - czas trwania

frequency – (recurrence, periodicity) - częstotliwość

data – sg. datum- ( information in anelectronic form that can be stored and used by a computer) - dane

input (v.) – (load) - wprowadzać

take measurements – dokonywać pomiarów

storage device – urządzenie magazynujące

acquire – (achieve, get) – nabywać, uzyskiwać

fetus – (a young human being or animal before birth, after the organs have started to develop ) - płód

currently – (at present, nowadays) - obecnie

TASKS:

I. Answer the questions:

1. What does a typical ultrasound machine consist of?

2. What animals make use of echolocation?

3. When do sound waves get reflected in the body? Give examples.

4. What picks up the reflected waves?

5. What's the speed of sound in different tissues?

6. How many pulses are sent and received each second?

7. What other types of ultrasound are in use nowadays?

II. Complete the text below by choosing one appropriate word from each pair for each gap.

CAPABLE/ENABLE MOVED/MOVING DEVELOPED/DEVELOPING ECHOES/SCANS SOFTWARE/HARDWARE

In the past several years, ultrasound machines ………………………… of three-dimensional imaging have been ……………………………. In these machines, several two-dimensional images are acquired by ………………………… the probes across the body surface or rotating inserted probes. The two-dimensional ……………………… are then combined by specialized computer ………………………… to form 3-D images.

III. Complete the phrases below and match their translations:

1. m _ _ i_ _ _ _ _ _ _ in_ _e_ _ _ _ q _ _

2. _ _ _h _ _ _ q _ _ _ _ y _ _ u _ _ _ _ v _ _

3. _ _ _ _u _ _ _ _ the d _ _ _ _ _ _ e

4. _ _ _s _ s are _ _ _t and _ _ _e _ _ e _

5. _ _ _ _ s _ _ _ e _ _ _ o _ _

6. _ _ n _ _ _ _ _ _ _ _ _ ss _ _ _ _ _ _t

7. _ _ _ _ _ the _ _ _ _u _ _ _ _ o _ _

8. _ _ _n _ _ the a _ _ _ _ _ _ _ e, f _ _ _ u _ _ _ _

and _ _ _ _ _ i _ _

9. _ _ p _ _ _ _ _ a

10. _ _ _ _e the a _ _ _ _ r_d _ _ _ g _ _

IV. PRESENT SIMPLE PASSIVE. Change active sentences into passive and passive into active ones:

1. Bats use echolocation.

2. The machine transmits sound pulses.

3. The waves are relayed to the machine.

4. The machine calculates the distance.

5. A two-dimensional image is shown on the display.

6. A CPU does all the calculations.

7. The measurements are taken by the cursor.

8. All images are stored on the disc.

V. PAST SIMPLE PASSIVE. Change the sentences from task IV into Past Simple, either passive or active.

1.

2.

3.

4.

5.

6.

7.

8.

EXTRA READING:

-----------------------

fale dźwiękowe o wysokiej częstotliwości

A. impulsy są wysyłane i odbierane

B. obliczać odległość

C. procesor

D. przechowywać uzyskane obrazy

E. sonda przetwornika

F. technika obrazowania medycznego

G. wprowadzać dane

H. wykonywać wszystkie obliczenia

I. zmieniać amplitudę, częstotliwość i czas trwania

The propagation speed of sound waves through tissue is an important element of ultrasound scans. Ultrasound machines assume sound waves travel at a speed of 1540 m/sec through tissue. In reality, the speed of sound is affected by the density and elasticity of the medium through which it is traveling and these factors are not constant for human tissues. The propagation speed of sound is higher in tissues with increased stiffness and density .Examples of propagation velocities in different tissues are given below :

air: 330 m/sec fat: 1450 m/sec

water: 1480 m/sec liver: 1550 m/sec

kidney: 1560 m/sec blood: 1570 m/sec

muscle: 1580 m/sec bone: 4080 m/sec

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download