How does a scan work?

SCANNER in Paris

Make a ct-scan in Paris

What is a scanner?

A CT scan is an X-ray examination performed using specialized equipment. It is used to obtain cross-sectional images and views from different angles of the body's interior. CT scans can examine internal organs, bones, lungs, brain, soft tissues and blood vessels.
Depending on the context, a CT scan of the relevant body part is performed.
For example, to help diagnose cancer, a chest ct-scan,a CAP CT Scan or an abdominal-pelvic CT scan may be performed.
However, thearthroscanner is an example of a scanner used to treat osteoarticular pathologies.

How does a scan work?

You'll lie on a bed that moves in a wide ring, usually on your back and alone in the examination room; we'll be able to communicate with you via a microphone. The team is right next to you, behind glass. They can see and hear you throughout the examination. If necessary, they can intervene at any time.
Depending on the area being examined, your arms will be at your side or behind your head. The examination is generally rapid. Your cooperation is important: you should try to remain still; in some cases, we'll use the microphone to tell you when to stop breathing for a few seconds. You will stay in the scanner room for an average of 10 minutes. Some examinations require an intravenous injection, usually at the elbow, or a drink.

 

Is the scanner dangerous?

As far as patient irradiation is concerned, no risk has been demonstrated, given the low doses used and the precautions taken to limit the area examined to the strict minimum. By way of example, a single x-ray corresponds on average to the average natural exposure (sunlight) experienced during a 4-hour plane journey.
However, for pregnant women, precautions must be taken systematically: that's why it's important to let us know if you might be pregnant.

Allergy to contrast medium

Some people with an allergic background may be exposed to an exacerbation of their symptoms when contrast media is injected. To limit the risk, premedication is recommended. In all cases, you should discuss your condition before the examination. If you have a history of severe allergy, in particular a history of facial edema (Quincke's type) or giant urticaria, following an injection during a previous radiological examination, NO injection will be carried out. On the other hand, no cross-allergy has been proven. Just because you can't stand oysters or strawberries doesn't mean you're more at risk of developing an allergy than others.

Do you have to undress for a CAT scan?

Some examinations, notably chest scans, require the patient to undress, at least the top, for better examination quality. Generally speaking, to undergo a CT scan, it is advisable to undress. This technology differs from MRI, an examination for which the patient is not asked to undress.

During scanner examination

Follow the instructions carefully; your cooperation is essential to ensure that images are not blurred. If you feel any pain during the injection, report it immediately.

Do you have to fast?

Some tests require an empty stomach for proper analysis. This will be explained to you when you book your appointment. In this case :

  • Do not swallow solid food for 4 hours before the appointment.
  • You should continue to take all your medications as usual.
  • A small snack (a coffee and a cookie in the morning) is still allowed.
  • But unless otherwise indicated, drink water as usual.

An injection for a CT scan: which ones and what are the risks?

Iodine-based products that are opaque to X-rays will be used. The type of iodine used and the way it is administered will be adapted to your particular case by the radiologist. This choice will depend in particular on the information on your state of health that you provide before the examination.
In the vast majority of cases, you won't feel any pain. However, in the case of intravenous injections, it is not uncommon to feel a sensation of heat at the moment of injection, or a strange taste in the mouth.

CT scans and pregnancy

If you are pregnant, X-rays should be avoided as far as possible to limit exposure of the foetus.
A CT scan may, however, be prescribed by your doctor in very specific cases, in particular to assess the size of the pelvis in the last trimester before delivery, to help the obstetrician-gynecologist decide between a vaginal delivery or a Caesarean section. This is known as pelvimetry or pelviscanner, and is performed with very low doses of radiation. In other cases, it must be discussed on a case-by-case basis.
If you may be pregnant, or if in doubt, you must inform the medical team before the examination.

Injection risks

Injection is a very common procedure, usually perfectly tolerated. However, as with any medication, rare side effects may occur.
The sting may cause a small hematoma, which is not serious and will spontaneously heal within a few days.
During injection, pressure may cause the product to leak under the skin, into the vein. This complication is rare (one case in several hundred injections, generally without serious consequences), and may exceptionally require local treatment.
Injection of iodinated products may lead to an intolerance reaction. These unpredictable reactions are more frequent in patients who have already had a poorly tolerated injection of one of these products, or who have a history of allergy. They are generally transient and not serious.
They can be more severe, leading to cardio-respiratory problems and the need for treatment.
Truly serious complications are in fact extremely rare.
Renal accidents, also linked to the iodized product, are also possible, particularly in subjects suffering from diseases that weaken the kidney (chronic renal failure, diabetes with renal insufficiency, etc.).
Please inform us of any kidney problems before the examination.

Special procedures will be followed in the case of specific risk factors, which will be identified during the dialogue between you and the team. In all cases, if you think you may have a risk factor, you must mention it when you book your appointment.

Just before the exam

For greater comfort, we recommend using the toilet, unless otherwise indicated.
During the examination, follow the instructions carefully; your cooperation is essential to ensure that the images are not blurred. If you feel any pain during the injection, report it immediately. 

Is the examination painful?

NO. Going through the scanner is completely painless, like having your photo taken.

Should I postpone if I have my period?

No, this does not affect the interpretation of the scan.

After your return home

In the vast majority of cases, you won't feel anything in particular. However, don't hesitate to let the team know if anything seems out of the ordinary.

It's normal to have questions about the exam you're about to take.
We hope we've answered your questions. Please do not hesitate to contact us again should you require any further information.

To bring on the day of the exam

  • your doctor's request (prescription, letter, etc.)
  • a written list of the medications you are taking,
  • X-ray records in your possession (X-rays, ultrasounds, scans, MRIs)
  • all your blood test results.  

 

Results

An initial commentary may be given immediately after the examination, but this is only a first approach, as the images must then be analyzed on a computer by the radiologist.
The written report will be available as soon as possible. 

Can I come by car?

The street is pedestrianized, you can park in front of the establishment for 1/2 hour, and Paris city parking lots are 3 minutes from our establishment (e.g. parking réaumur ...).

You'll be perfectly fine to drive after your examination, except in the case of arthro-scan (scanner with injection into a joint), where it's best to avoid doing so, as the joint is a little sensitive for a few hours.
If you've arrived on an empty stomach, it's advisable to eat and drink before getting back behind the wheel.

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