Common questions about MRI
Surely, your radiologist or treating physician has already explained a lot about the exam to you. Nevertheless, sometimes there are unanswered questions that only occur to you later, after the initial discomposure has passed. We have collected the most common questions below.
Is MRI or ultrasound scanning radiation-free?
MRI is completely radiation-free. The images are produced by placing the patient in a strong magnetic field, so that all of the atoms in the patient (a human being consists primarily of hydrogen atoms) align in a single direction in the magnetic field and then small individual portions of the volume of the body are briefly subjected to an additional magnetic pulse using precisely calculated electromagnetic excitation (this is the source of the loud knocking noise during the exam) to change their direction. Once the impulse has been shut off, these portions revert to their original state very quickly. The speed of this process varies with the properties of the examined tissue, and can be measured, so that images that depict the composition and state of the tissue can be calculated.
An ultrasound examination requires an ultrasonic probe in which high-frequency waves are produced. These are transmitted into the body, where they are reflected differently depending on the composition of the tissue. A receiver is also installed in the probe head, which records these reflected sound waves (sometimes deflected or at a modified frequency.) By calculating the change in the transmitted signal, typical ultrasonic images can be calculated. Just like MRI, ultrasound exams are absolutely free of radiation. The electromagnetic waves used are completely harmless and cannot be perceived by the body.
I have claustrophobia and am supposed to get an MRI. What should I do?
Many people experience a feeling of claustrophobia when they get their first look at an MRI machine.
To ease your fears: For some exams (such as MRI scanning of the knee or ankle), the head does not need to enter the machine. Many modern machines are already much more spacious and more patient-friendly. Our MR machine at our center city location, for example, has an extremely short and very wide rube. It is a “semi-open” 1.5 Tesla system with extremely good image quality. The machine has much higher image resolution than the previous classical open “sandwich MRI” style, which makes it a true alternative for quality reasons as well. We therefore share the opinion of regional university clinics, which are now all using these “semi-open” systems. It is therefore always worthwhile to discuss the exam in detail with the physician who will perform it, and to take a closer look at the machine. A reassuring discussion, many radiologists have found from experience, can help to calm fears. If the problem persists, in rare cases a sedative can also be given. This taken in pill form or injected intravenously prior to the exam. This means that MR exams can be used on pretty much anyone, even patients with massive claustrophobia. One disadvantage is that your concentration is reduced, so you can definitely not drive yourself home after the exam.
If a felling of claustrophobia arises or becomes unbearable only once the exam is underway, you can always make contact with the examining physician or our employees, as you can press the emergency call button in your hand.
When am I not allowed to have an MRI?
Click here to learn more about contraindications for MRI …
Is MRI safe to use during pregnancy?
An MRI exam should not be performed during the first trimester of pregnancy, if possible. Damaging effects of MRI on the fetus have not been proven, but an exam should nevertheless be performed only in exceptional cases and for an important reason. Administration of a contrast agent should always be avoided during pregnancy except when absolutely necessary in life-threatening situations. Due to the high level of noise during the exam (the mother receives hearing protection), the child may be awakened during the exam. Because there is no documentation of any hearing damage, the use of an MRI exam during pregnancy should be considered very carefully. If the pregnant patient requires diagnostic imaging, however (such as very severe, acute headaches), then MRI should be preferred over an X-ray exam in all cases.
What do I need to do for a cardio MRI and cardio CT?
The typical contraindications for MRI apply to cardio MRI. Click here to learn more about contraindications for MRI …
Please bring a current letter from your physician and current blood test results. Avoid caffeinated beverages or performance-enhancing agents on the day of the exam. Erectile dysfunction medications (such as Viagra) must be avoided for at least 24 hours prior to the exam.
May an accompanying person join me for the MRI exam?
There is no reason that a companion could not be present for the exam. Especially patients who suffer from claustrophobia can often benefit from the presence of a trusted person. For all persons present for the MRI, of course, the same safety rules apply as for the patient (no metal, pacemakers, etc.)!
Click hier to learn more about contraindications for MRI …
Can’t I have several organs or joints examined in a single session?
In case of urgent clinical indication, we perform exams on several regions of the body in special cases. The problem with this is that often the longer exam time means increasing movement on the part of the patient, so the images become worse and lose focus over the course of the exam. With the additional background that only one examination region is covered by statutory insurance each quarter, and due to the quality reasons mentioned above, multiple examinations can be done only in exceptional cases.