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Файл:Введение в биомедицинскую инженерию. Учебное пособие
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herniated discs, epilepsy, encephalitis, spinal stenosis, a blood clot or
intracranial bleeding in patients with stroke, brain damage from head
injury, and other disorders.
Scanning takes about 20 minutes. The patient lies on a special table
that slides into a narrow chamber. A sound system built into the
chamber allows the patient to communicate with the physician or
technician. X-rays are passed through the body at various angles and are
detected by a computerized scanner. The data is processed and displayed
as cross-sectional images of the internal structure of the body or organ.
Electroencephalography (EEG), monitors brain activity through
the skull. EEG is used to help diagnose certain seizure disorders, brain
tumors, brain damage from head injuries, inflammation of the brain or
spinal cord, alcoholism, certain psychiatric disorders, and metabolic and
degenerative disorders that affect the brain. EEGs are also used to
evaluate sleep disorders, monitor brain activity when a patient has been
fully anesthetized or loses consciousness, and confirm brain death.
A series of cup-like electrodes are attached to the patient’s scalp,
either with a special conducting paste or with extremely fine needles.
The electrodes (also called leads) are small devices that are attached to
wires and carry the electrical energy of the brain to a machine for
reading. A very low electrical current is sent through the electrodes and
the baseline brain energy is recorded. The electrodes transmit the
resulting changes in brain wave patterns. Since movement and
nervousness can change brain wave patterns, patients usually recline in a
chair or on a bed during the test, which takes up to an hour.
Electromyography (EMG) is used to diagnose nerve and muscle
dysfunction and spinal cord disease. It records the electrical activity
from the brain or spinal cord to a peripheral nerve root (found in the
arms and legs) that controls muscles during contraction and at rest.
During an EMG, very fine wire electrodes are inserted into a
muscle to assess changes in electrical voltage that occur during
movement and when the muscle is at rest. The electrodes are attached
through a series of wires to a recording instrument. Testing usually lasts
about an hour.
An EMG is usually done in conjunction with a nerve conduction
velocity (NCV) test, which measures electrical energy by assessing the
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nerve’s ability to send a signal. A technician tapes two sets of flat
electrodes on the skin over the muscles. The first set of electrodes is
used to send small pulses of electricity (similar to the sensation of static
electricity) to stimulate the nerve that directs a particular muscle.
The second set of electrodes transmits the responding electrical signal to
a recording machine. The physician then reviews the response to verify
any nerve damage or muscle disease. There is no discomfort or risk
associated with this test.
Electronystagmography (ENG) describes a group of tests used to
diagnose involuntary eye movement, dizziness, and balance disorders,
and to evaluate some brain functions. Small electrodes are taped around
the eyes to record eye movements. If infrared photography is used in
place of electrodes, the patient wears special goggles that help record the
information. Both versions of the test are painless and risk-free.
4. Read the text about MRI scans diagnostics:
MRI Scans Diagnostic
Magnetic resonance imaging (MRI) uses computer-generated
radio waves and a powerful magnetic field to produce detailed images of
body structures including tissues, organs, bones, and nerves.
Neurological uses include the diagnosis of brain and spinal cord tumors,
eye disease, inflammation, infection, and vascular irregularities that may
lead to stroke. MRI can also detect and monitor degenerative disorders
such as multiple sclerosis and can document brain injury from trauma.
The equipment houses a hollow tube that is surrounded by a very
large cylindrical magnet. The patient, who must remain still during the
test, lies on a special table that is slid into the tube.
MRI scanning equipment creates a magnetic field around the body
strong enough to temporarily realign water molecules in the tissues.
Radio waves are then passed through the body to detect the «relaxation»
of the molecules back to a random alignment and trigger a resonance
signal at different angles within the body. A computer processes this
resonance into either a three-dimensional picture or a two-dimensional
«slice» of the tissue being scanned, and differentiates between bone, soft
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tissues and fluid-filled spaces by their water content and structural
properties. A contrast dye may be used to enhance visibility of certain
areas or tissues. Depending on the part(s) of the body to be scanned,
MRI can take up to an hour to complete. Due to the incredibly strong
magnetic field generated by an MRI, patients with implanted medical
devices such as a pacemaker should avoid the test.
Positron emission tomography (PET) scans provide two- and
three-dimensional pictures of brain activity by measuring radioactive
isotopes that are injected into the bloodstream. PET scans of the brain
are used to detect highlight tumors and diseased tissue, measure cellular
or tissue metabolism, show blood flow, evaluate patients who have
seizure disorders that do not respond to medical therapy and patients
with certain memory disorders, and determine brain changes following
injury or drug abuse, among other uses. A low-level radioactive isotope,
which binds to chemicals that flow to the brain, is injected into the
bloodstream and can be traced as the brain performs different functions.
The patient lies still while overhead sensors detect gamma rays in the
body’s tissues. A computer processes the information and displays it on
a video monitor or on film. Using different compounds, more than one
brain function can be traced simultaneously.
Single photon emission computed tomography (SPECT), a
nuclear imaging test involving blood flow to tissue, is used to evaluate
certain brain functions. The test may be ordered as a follow-up to an
MRI to diagnose tumors, infections, degenerative spinal disease, and
stress fractures. As with a PET scan, a radioactive isotope, which binds
to chemicals that flow to the brain, is injected intravenously into the
body. Areas of increased blood flow will collect more of the isotope. As
the patient lies on a table, a gamma camera rotates around the head and
records where the radioisotope has travelled. That information is
converted by computer into cross-sectional slices that are stacked to
produce a detailed three-dimensional image of blood flow and activity
within the brain.
5. Answer the questions according to the text:
1. What can MRI detect?
2. What does the equipment house?
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3. Is the procedure of MRI complex?
4. How is it performed?
5. How long does it take?
6. What does PET provide?
7. Why is SPECT important for diagnostic imaging?
6. Read about ultrasound diagnostic and answer the following
questions:
1. What is ultrasound?
2. Is ultrasound effective for diagnostic?
3. How is ultrasound performed?
4. How long does the test take?
5. Why do scientists develop diagnostic research?
Ultrasound Diagnostic
Ultrasound scanning or sonography, uses high-frequency sound
waves to obtain images inside the body. It analyzes blood flow in the
brain and can diagnose stroke, brain tumors, hydrocephalus (build-up of
cerebrospinal fluid in the brain), and vascular problems. It can also
identify or rule out inflammatory processes causing pain. It can show
tears in ligaments, muscles, tendons, and other soft tissue masses in the
back.
During ultrasound, the patient lies on an imaging table and removes
clothing around the area of the body to be scanned. A jelly-like lubricant
is applied and a transducer, which both sends and receives highfrequency sound waves, is passed over the body. The sound wave
echoes are recorded and displayed as a computer-generated real-time
visual image of the structure or tissue being examined. Ultrasound is
painless, noninvasive, and risk-free. The test takes between 15 and
30 minutes to complete.
Scientists continue to develop additional and improved screening
methods to more accurately and quickly confirm a specific diagnosis
and allow scientists to investigate other factors that might contribute
to disease. Technological advances in imaging will allow researchers to
better see inside the body, at less risk to the patient. These diagnostics
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and procedures will continue to be important clinical research tools for
confirming a neurological disorder, charting disease progression, and
monitoring therapeutic effect.
7. Look through the texts and find information about:
a) the advantages of modern diagnostic equipment
b) importance of clinical research tools for confirming disorders
c) the disadvantages of diagnostic tools
8. Scan the texts again and answer: true, false or no
information. Explain your answers with the information from the
text:
a) medical equipment can create pictures of the structures and
activities inside the body;
b) types of diagnostic imaging are electromagnetic waves;
c) in physics radiation describes any process in which energy
emitted by one body travels space to be absorbed by another body;
d) CT scan is a painful procedure;
e) EEG is used to evaluate to sleep disorders only;
f) MRI can take up to 5 minutes to complete;
g) SPECT is used to evaluate certain brain functions;
h) scientists do not develop improved diagnostic methods
Comprehension check
1. Match the following words with their translations:
1) spinal cord a) сосудистый
2) examine b) боль
3) absorb c) воспаление
4) pain d) устройство
5) low-dose radiation e) вмещать
6) two-dimensional f) высокочастотный
7) tumor g) завершать
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8) inflammation h) записывающее устройство
9) attach i) способность
10) device j) увеличить
11) recording instrument k) исследовать
12) ability l) прикреплять
13) detect m) в двух измерениях
14) house n) впитывать
15) magnetic field o) низкая доза радиации
16) complete p) обнаружить
17) increase q) опухоль
18) high-frequency r) магнитное поле
19) vascular s) припадок
20) seizure t) спинной мозг
2. Read the descriptions of diagnostic tests (1 – 10) and match
them with the letters (a – j):
1. ______ is used to diagnose involuntary eye movement, balance
disorders and to evaluate some brain functions;
2. ______ is used to evaluate certain brain functions;
3. ______ is used to produce continuous images of a body part in
motion;
4. ______ is used to diagnose certain seizure disorders, brain
tumors, alcoholism and to evaluate sleep disorders;
5. ______ is used to view any part of the body;
6. ______ is used to diagnose brain and spinal cord tumors, eye
disease, inflammation and infection that may lead to stroke;
7. ______ is used to produce rapid, clear two-dimensional images
of organs, tissues and bones;
8. ______ is used to analyze blood flow in the brain. It can
diagnose stroke, brain tumors and vascular problems;
9. ______ is used to diagnose nerve and muscle dysfunction and
spinal cord disease;
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10. ______ is used to detect tumors and disease tissue, to show
blood flow, to determine brain changes
a) EEG, b) PET, c) radiograph, d) MRI, e) ENG, f) sonography,
g) CT scan, h) SPECT, i) fluoroscopy, j) EMG
3. Complete the sentences using the information from the texts
about diagnostic imaging:
1) Diagnostic techniques create pictures of…
2) The diagnostic tests are performed at…
3) During X-ray examination the bony structures appears…
4) Scanning takes…
5) During an EMG the electrodes are attached through…
6) During an ENG small electrodes are placed around…
7) MRI scanning allows a contrast dye to…
8) PET scans provide…
9) During sonography a jelly-like lubricant…
10) Ultrasound is painless and …
Vocabulary
1. Guess the meaning of the following words and wordcombinations:
1) diagnose, 2) technology, 3) medical, 4) structure, 5) symptom,
6) scanner, 7) test,
8) machine, 9) radiation, 10) dosage, 11) examine, 12) organ,
13) system, 14) calcium,
15) mass, 16) contrast, 17) epilepsy, 18) patient, 19) alcoholism,
20) electrodes, 21) electrical energy, 22) nerve, 23) instrument,
24) signal, 25) muscle, 26) photography, 27) sclerosis,
28) cylindrical magnet, 29) relaxation, 30) molecules, 31) radioactive isotope, 32) therapy, 33) chemical, 34) video monitor,
35) function, 36) analyze, 37) problem, 38) jelly, 39) risk, 40) factor,
41) procedure, 42) clinic, 43) hospital, 44) echo, 45) anesthesia.
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2. Match the word with their synonyms:
1) examine a) record
2) physician b) imaging center
3) clinic c) film
4) dose d) picture
5) test e) investigate
6) tape f) technician
7) device g) finish
8) complete h) concentration
9) description i) procedure
10) video monitor j) instrument
3. Match the word with their antonyms:
1) high-frequency a) outside
2) narrow b) dangerous
3) comfort c) begin
4) rapid d) wide
5) risk-free e) disadvantage
6) visible f) low-frequency
7) inside g) at rest
8) complete h) invisible
9) in motion i) slow
10) advantage j) discomfort
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4. Fill in the blanks using the words from the list:
1. X-rays are detected by a ____________.
2. Sonography takes about ____________ to complete.
3. ___________ continue to develop improved screening methods.
4. The diagnostic tests are painless and ____________.
5. High-frequency sound waves pass over the ____________.
6. Fluoroscopy is a type of X-ray with ____________.
7. MRI scanning equipment creates a _________ around the body.
8. CT scans are used to view the spine and ____________.
9. A computer displays ____________ on a video monitor.
10. During a procedure a patient should lie on an ____________.
а) information, b) imaging table, c) low-dose radiation,
d) compurized scanner, e) half an hour, f) scientists, g) brain,
h) magnetic field, i) body, j) risk-free.
Discussion Point
1. Comment on the essence of diagnostic imaging.
2. Define the main types of diagnostic equipment using the key
words and word-combinations given below:
1) doctors use to look,
2) technology will depend on,
3) painless and easy,
4) the dosage is low,
5) to examine,
6) can be used to view,
7) to detect,
8) the test takes about,
9) X-rays are passed through,
10) tests are performed at,
11) equipment houses,
12) a patient lies on,
13) diagnostics and procedures will continue to,
14) scientists go on to,
15) diagnostic imaging is important for
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3. Try to tell about diagnostic equipment using the schemes
quip
given below:
X-ray
ment
e
radiograph fluoroscopy
MRI scans
PET SPECT
EEG ENG
ST scans
EMG
Ultrasound
equipment
sonography neurosonography
4. Have you ever used X-ray equipment for your diagnostic?
Can you describe the procedure of the test?
5. Have you ever been examined with the help of CT scans
equipment? What diagnostic units were used? Describe the
procedure of scanning.
6. What can you tell about the test of MRI scanning? Have you
ever been examined with it? What diagnostic devices were used?
7. Is ultrasound diagnostic important? Have you ever been
tested with this device? Is the procedure comfortable? Describe it.
Video
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