What does the term "X-ray" mean and how long is
this procedure in use?
What is the difference between conventional and digital X-rays?
What does fluoroscopy mean?
Are X-rays dangerous?
Why is mammography so important?
Isn’t it enough if one just palpates the breast regularly?
Can one distinguish between benign and malignant changes?
What are the risks of a mammography?
How is the investigation performed?
When is a mammography indicated?
What is a “digital mammography”?
What is an MRT investigation of the breast and when is it
performed?
What does the term "Digital Mammography" mean?
What are the advantages of digital microdose mammography?
What is the difference between digital and analogue mammography?
Is it possible to achieve better evaluation with a lower radiation dose?
What changes are indicative of a possible disease in the breast and should be investigated further by low-radiation mammography?
Why is it so important to localise small calcifications in breast tissue by means of mammography?
What does the term "osteoporosis" mean?
What does measurement of bone density (bone densitometry) mean?
What are the causes of osteoporosis?
From what age onward should one undergo a bone densitometry?
What are the clinical signs of osteoporosis?
Are there self-help groups?
Is ultrasonography the same procedure as ultrasound?
How does ultrasonography work?
Which structures are best investigated by this procedure?
What is Duplex ultrasonography?
How is an ultrasonography investigation performed
Since when does computed tomography exist and what are
the features of this procedure?
Which structures and organs are visualised particularly well
on CT?
Why is it necessary to administer contrast medium before
the investigation?
By which pathway is contrast medium eliminated?
When should a CT never be performed?
What is the radiation dose used for a CT investigation?
I suffer from claustrophobia. Is computed tomography the
investigation that uses a narrow tunnel?
Is there a difference between magnetic resonance imaging
and nuclear resonance scanning?
What is magnetic resonance imaging (MRI)?
What does Tesla mean?
What is the strength of the magnets used for medical purposes?
How common are magnetic resonance imaging units?
What is the advantage of MRI?
Do metals act as interferences when a nuclear resonance
imaging scan is performed?
What are the factors that indicate one should not perform
a nuclear resonance tomography?
What about the side effects?
Does one feel claustrophobic or experience states of anxiety
within the device?
The German physicist Wilhelm Conrad Roentgen who was born in 1845 discovered,
in 1895, that electromagnetic rays of a specific wavelength penetrate the
body and are partly absorbed by it. By using the roentgen rays named after
Wilhelm Conrad Roentgen, organs within the body can be visualized in a
similar way as objects are visualized by the use of a camera.
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In conventional X-rays the image is exposed on film - a method no longer
in use at DiagnoseZentrumUrania. In the most modern form
of X-rays, which is digital X-ray, the image is transformed into digital
signals and further processed by a computer. The radiation dose is significantly
reduced by this procedure ? by about a third or a half. The images need
not be repeated because incorrect exposures can be corrected at the workplace
and processed there if necessary. The DiagnoseZentrumUrania stores
the data in digital form and sends them by the electronic route ? for instance,
to hospitals, so repeat examinations need not be performed.
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In this investigation the patient is "fluoroscopied" (transilluminated)
with X-rays in a way that the radiologist is able to view the moving organs
on a monitor and evaluate them. However, the procedure is used less and
less now. In DiagnoseZentrumUrania, for instance, the large intestine is investigated by
computed tomography (CT), by performing a so-called virtual colonoscopy
(Computed tomography). CT is
also used instead of X-ray fluoroscopy of the lung in some instances. However,
for the investigation of specific symptoms in the stomach and the oesophagus,
fluoroscopy still is an important procedure.
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The damaging effect of X-rays depends on the quantity (dose) used. The
advancements made over the last 100 years have consistently reduced the
degree of damage. Today the dose is in a range that may be considered nearly
safe. Of course X-rays are used as sparingly as possible. During pregnancy
they should be completely avoided. Instead, procedures such as ultrasonography
and magnetic resonance imaging are given preference here. Every investigation
method possesses its own strengths and advantages. In every case, the doctor
uses the safest and most informative procedure. Quite often it still is
the (digital) X-ray procedure (Radiation load in CT,
natural radiation).
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Breast cancer is the most common cancer in women. 8-10% of all women
are affected by breast cancer once in their lives. However, the disease
can be treated very well - provided it is detected in the early stage.
Regular early detection measures enhance the probability of cure. Mammography
is the most important preventive examination for early detection of breast
cancer.
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Palpating the breast is very important. Usually it is done by the treating
doctor, the gynaecologist in most cases, or even the woman herself. However,
this method allows one to detect tumours about 1 centimetre or more in
size. At this time most tumours have been growing for several years. Mammography,
on the other hand, identifies small nodes in a stage when they are not
in the least palpable.
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This is often the case - but, regrettably, not always. The most common
benign node in the breast is not a tumour but a cyst (fluid content). Nodes
consisting of tissue can be identified well on mammography. Some of them
contain very small calcium deposits (microcalcification) - these are a
typical sign of specific forms of cancer. The form and structure of the
changes also allow the investigator to distinguish between benign and malignant
tumours. All nodes that are not obviously benign are investigated nowadays
by means of histological examination (tissue specimen).
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Because of technical advancements, the radiation dose has been consistently
reduced in the last few years. Particularly digital mammography which is
used in DiagnoseZentrumUrania involves a very low radiation dose. In general, the principle
that applies to all X-ray investigations is also true for mammography:
a non-diagnosed malignant process causes greater suffering than the potential
side effects of the investigation.
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The patient places her breast on the X-ray table. The breast is comPressd
here as gently as possible. The patient informs the radiologist or the
medical-technical assistant when the pressure becomes too strong and she
feels it should cease. Compression is necessary, but it should not be painful.
The stronger the breast is comPressd, the better are the X-ray images and
the less is the radiation exposure. For the investigation one selects that
grade of compression which the patient is able to tolerate without significant
pain.
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At every investigation you must take ALL images and reports with you because
very small changes can be detected only by comparing the present images
with previous ones. Therefore, it is meaningful to perform a basic mammography
at the age of 35 years.
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It is performed in the same manner as the well known mammography procedure
using X-rays. However, the images are not produced on film, but are converted
into storable data on a so-called detector plate.
This offers the following advantages:
In a magnetic resonance tomography (INTERNAL LINK) the breast is investigated
with the aid of special contrast media. Contrast media accumulate to a greater
extent in malignant tumours than in normal breast tissue. The investigation
is performed only if one achieves no definite result with mammography and
ultrasonography.
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Digital mammography is performed in a similar fashion as X-ray mammography.
However, the images are not produced on film but on a so-called detector
plate, in the form of data that can be stored. The diagnosis is performed
directly at the monitor, immediately after the images are taken. Portions
of the images can be magnified and processed in a targeted manner.
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Suspicious foci and calcifications can be detected much more easily by
the digital procedure – simultaneously, the required radiation dose
is significantly reduced.
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Especially in cases of women with larger breasts, previously one had to
obtain several images of various portions of the breast. Due to the large
detector plate of microdose mammography, one only requires the classic images
“from above” and “from the side”. The excellent
quality of digital images is such that, as a rule, one needs fewer images,
which signifies a lower radiation dose.
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In a magnetic
resonance tomography the breast is investigated with the aid of special
contrast media. Contrast media accumulate to a greater extent in malignant
tumours than in normal breast tissue. The investigation is performed only
if one achieves no definite result with mammography and ultrasonography.
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The term osteoporosis literally means “porous bone”.
According to the definition of the WHO, osteoporosis (also known as bone
atrophy in colloquial language) is a skeletal disease marked by a low bone
mass and a disturbance of the micro-architecture of bone tissue, resulting
in fragile bones and an increasing risk of fracture. Typical fracture sites
are the vertebral column, the hip or the wrist.
Although we do not have accurate figures for the total number of people
suffering from osteoporosis, according to current estimates about 700,000
individuals in Austria suffer from osteoporosis; women account for about
80% of these persons.
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Bone densitometry is performed to investigate osteoporosis. The purpose is to establish the presence of the disease with certainty because a person who suffers from the disease will be more susceptible to fractures. The risk can be significantly reduced by early prevention and treatment of the disease.
Measurement of the calcium content of bone (also known as bone densitometry)
is the basis of any diagnostic procedure for osteoporosis. It is performed
at DiagnoseZentrumUrania by means of dual-spectrum X-ray
absorptiometry (= DEXA, Dual-Energy
X-Ray-Absorptiometry).
This method of investigation is particularly used for the lumbar spine and
the neck of the femur. It is marked by a very high degree of precision,
requires very low doses of ionizing rays, is considered the gold
standard (method of first choice), and permits calculation of the
bone mineral content in the region of investigation.
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Like all living tissue, human bone is subject to an ongoing process of
remodelling. In other words, bone is continuously renewed. One of the several
functions of sex hormones (oestrogen, testosterone) is to regulate this
process. An individual achieves his/her maximum bone mass at the age of
about 35 years. After this age, bone mass reduces. The altered hormonal
balance of the body in advanced age leads to greater degenerative activity,
so that bone mass is permanently lost and the bearing structure within bone
is reduced. Consequently, the risk of fracture increases.
Particularly after menopause – between the age of 50 and 55 years
– a rapid loss of bone mass starts to occur. Owing to the reduction
of the female sexual hormone, oestrogen, and also gestagen, many women experience
accelerated bone loss, which may be more than 3.5% to 8% per year. Thus,
osteoporosis most commonly (up to 95%) occurs in women after the last spontaneous
menstrual bleeding, i.e. during menopause.
Besides, it should be noted that osteoporosis may occur as a consequence
of other basic diseases in men and women (secondary osteoporosis).
A bone densitometry is indicated in the following persons:
The following are risk factors:
As the quality of bone in the human body is best around the age of 30 years,
it would be advisable to undergo a first preventive densitometry around
the age of 35 years.
Regular controls should be performed from the age of 50 onward for timely
prevention of fractures and, depending on the individual’s fracture
risk, to initiate drug treatment that will minimize the risk of fractures.
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Typical signs are fractures of the vertebral column, the neck of the femur and the wrist.
Osteoporotic fractures may occur spontaneously while standing, walking or sitting – and even while sleeping. Simple movements such as lifting a shopping bag or carrying your grandchild may cause a fracture. Each fracture increases the risk of suffering the next one.
Osteoporosis and vertebral fractures may lead to deformation of the vertebral
column (so-called hunchback), which may limit respiratory function or cause
painful and problematic displacement of internal organs.
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Help for Self-help
In addition to physical symptoms, osteoporosis frequently causes
psychological problems such as insecurity, stress or fear which, in turn,
may trigger loss of self-esteem or depression.
Exchanging one’s experiences with other patients who suffer from osteoporosis
helps one to deal better with the disease and also contributes significantly
to the enhancement of your quality of life.
Austrian Osteoporosis Self-help provides extensive information about the medical and psychological effects of the disease and will be glad to answer any questions concerning prevention, care and treatment of the patients.
Currently you will find active self-help groups for osteoporosis www.osteoporose.cc in the following places:
Yes, it is one and the same procedure.
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Ultrasound waves are sound waves we are unable to hear. Their physical
behaviour is different from that of sound waves we are able to perceive.
When ultrasound waves are sent through the body they don’t simply
pass through. They are reflected or sent back - within certain tissues.
The manner in which this occurs is used to visualise organs.
As these waves are sound waves, the investigation does not cause any injury.
Therefore the procedure can be safely used even during pregnancy – in
fact, it was developed for the very purpose.
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Vessels and soft-tissue structures can be seen very clearly; the same
is true for superficial structures lying directly under the skin - e.g.,
the thyroid, the female breast gland, lymph nodes, and testicles. Organs
of the abdominal cavity such as the liver, gallbladder, spleen, pancreas,
kidneys, uterus, ovaries, bladder and the male prostate gland are also
seen excellently by this procedure. Air and calcium remain invisible on
ultrasonography. All bones, the lung and those parts of the abdominal cavity
that contain intestinal gases (stomach, intestines) are therefore not seen
at all or seen to a limited extent on ultrasonography.
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It is a combined procedure consisting of conventional ultrasonography
to depict vessels, and so-called Doppler ultrasonography which allows one
to measure flow velocities in vessels. The Doppler effect of the wave was
discovered by the Austrian mathematician and physicist Christian Andreas
Doppler (born in Salzburg in 1803).
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First the patient is positioned according to the region the investigator
wants to study. The doctor applies a gel on the transducer. This serves
to improve the contact with the transducer. Without this gel there remains
a narrow strip of air between the transducer and the skin and the ultrasound
waves will be reflected by this strip of air. This will hinder viewing
the region behind, i.e. the organs to be investigated. During the investigation
of the abdominal cavity the patient must remain fasting because there are
relatively less intestinal gases in this state. Intestinal gases are a
significant source of disturbance. The doctor moves the transducer in different
directions and angles over the patient's skin in order to view and assess
the organs and the tissue from different perspectives. As far as possible,
the images are taken in standard directions so doctors who have not produced
the images themselves will also be able to gain information from them.
After the investigation has been completed the gel is removed.
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In the 1960's EMI (Electric and Musical Industries in England) made a
contract with the Beatles. The group succeeded and EMI made enormous profits.
A highly talented technician named Hounsfield worked in this company. One
day he received an unusual offer. He was asked to discover something new
in some field of research - he was given no specific data. He started to
look for new methods to depict the inner parts of the body. According to
him, it would be possible to send X-rays on several axes through the body,
assess the results with a computer, and thus create a tomogram without
overlap. In 1968 he was first able to depict the brain of a pig in this
manner. The machine "scanned" for nine days and the computer took 2 hours
to calculate the 28,000 measurements. The first investigation in a human
being was performed in 1971. For this discovery Hounsfield received the
Nobel prize for medicine in 1979. Today there are no CT units of EMI in
the market. The several years of research proved to be a very expensive
venture.
The special feature of computed tomography is the fact that the structures
of the various organs can be depicted without overlap. The brain, for instance,
is fully surrounded by bone and could be visualized only with the help
of this new procedure. All other internal organs can be assessed better
and more exactly with this method than with ordinary X-rays.
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The brain and brain marrow, all internal organs, the lungs and bone are
seen particularly well on CT.
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Contrast media (CM) possess a different density than body tissue and therefore
create better contrast (as the name suggests). After a contrast medium
is injected, it is enriched by organs that are richly supplied with blood.
This causes the liver, spleen, brain, etc. to be visualised much better.
Most tumours and inflammations are also supplied more strongly with blood
and therefore seen in sharp contrast to their surroundings. In fact, some
tumours have a typical vascularisation pattern which can be identified
only by the administration of contrast media. Besides, in certain cases
the administration of contrast medium allows the investigator to distinguish
between benign and malignant tumours. Joints and other body cavities are
also visualised in an excellent manner after the injection of CM. As CM
is eliminated via the kidney, the urinary tract and the bladder are seen
very clearly. Contrast media that you take in fluid form are deposited
in the walls of the intestinal tract, which also makes these organs visible.
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The injected contrast medium in blood, the body cavities, lymphatic tissue
or organs (liver, kidney) is nearly completely eliminated through the kidneys
within 15 to 30 minutes. The contrast medium you drink does not react with
the body and is eliminated naturally through the intestines. Some contrast
media, known as bile-permeable contrast media pass through the liver and
the bile ducts and then enter the intestines.
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The radiation dose is very low. It is similar to that for an X-ray or
a fluoroscopy. In principle, an investigation should not be avoided because
of high irradiation because an incorrect diagnosis could be disadvantageous
for the patient. Even in daily life we are exposed to marginal doses of
radiation which do us no harm. In fact, the opposite is true: Low radiation
doses are used for purposes of cure (e.g. in Bad Gastein). Also when we
take a flight we receive a certain dose. A transatlantic flight is approximately
equal to the radiation dose of a chest X-ray. The devices in use today
are much safer than they used to be earlier. Technical advancements are
continuously reducing the radiation dose for CT and digital X-rays.
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No, that is magnetic resonance tomography (MRT). The computed tomography
device does have a tunnel but the tunnel is much shorter - only about 50
cm. The body is nearly completely free. Basically there is no question
of claustrophobia during this investigation.
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No, the two are synonyms. The procedure is based on a very strong magnetic
field in which the pathways of electrons within the atomic nucleus change.
The former term refers to the magnetic field while the latter refers to
the processes that take place within the atomic nucleus.
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MRI is one of the most modern imaging procedures. One of the prerequisites
for MRI is a very strong magnetic field in which electrons in the nucleus
of the hydrogen atom are oriented differently under the influence of a
specific signal and ?return? to their original pathway when this signal
is removed. These small movements of the atoms can be measured and used
to create images.
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Tesla is the term used to define the strength of the magnet being used.
The stronger it is the faster one obtains images of highest quality. 1
Tesla equals 100,000 times the magnetic force of the earth. Magnets of
this type are difficult to manufacture and their operation requires the
amount of electricity that would be needed to run a small power plant.
The magnet must be continually cooled to 4? Kelvin (-256? centigrade) with
the liquid inert gas helium; nearly the same temperature is prevalent in
outer space. This magnetic field strength owes its name to the physicist
Nikola Tesla, who was born in Serbia in 1856, studied in Graz, and lived
and worked in the USA until 1943.
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The strength of the most commonly used devices in medicine is 1.0 to 3.0
Tesla. Stronger devices (up to 7 Tesla) are used solely for research purposes.
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In all, about 16,000 units are used in medicine. Of the latest generation
of devices, namely those of 3.0 Tesla, only 250 units are in use throughout
the world. One of them is in our office in the DiagnoseZentrumUrania. It is the only device
of this type in use in a radiology practice, i.e. outside a hospital, in
the entire EU. Austria is one of the leading countries, on par with the
USA, Japan and Switzerland, in terms of technical equipment, as well as
the quality of health systems.
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Soft tissues, especially the brain, bone marrow, vessels and joint cartilage,
can be assessed with MRI more accurately than with any other method. Changes
just a few millimetres in size can be identified by this procedure.
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Fillings in the teeth, joint prostheses, plates and screws inserted in
the body after fractures, may cause disturbances in the image, but do not
signify a hazard for the patient. Even in the presence of artificial cardiac
valves the investigation is usually safe.
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This procedure should not be used in patients with cardiac pacemakers.
Metal or shell fragments or metal clips with a large iron content, such
as those used in the past during operations on the cerebral vessels, may
well be sources of danger. Dentures, fixed braces or artificial hip joints,
on the other hand, are safe. Caution is advised in persons with tattoos
containing iron because these tend to become hot. In any case, you must
inform the medical staff of any metal parts in your body BEFORE the examination.
The magnetic field destroys bioelectronic implants (e.g., insulin pumps
in persons with diabetes, implants in the inner ear), as well as metal
parts of any type. Magnetic cards or electronic devices should not be brought
into the investigation room because these parts, as well as the magnetic
resonance unit, could be damaged by doing so.
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During the investigation you may experience muscular twitches or your
tissue might become slightly warm. These reactions are no cause for concern.
As a rule, the procedure can be performed safely even in children and pregnant
women. In the latter case, one may use devices with a lesser field strength.
Many patients find the noise within the device somewhat unpleasant; this
can be alleviated by the use of ear protection, ear plugs or headphones
with music.
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A small number of people (about 1%) find this type of investigation a
threatening experience. It helps when such people are accompanied by family
members or friends. Provided the accompanying person is calm, the course
of the investigation will not be hampered by their presence. During the
entire procedure, medical personnel will observe the patient through a
window. The patient can talk to the medical staff at any time. In addition,
patients can communicate with the medical staff at any time by pressing
an alarm switch. If necessary we administer a medication that relieves
anxiety; however, you should not drive a vehicle after this medication
is administered.
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