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What is MRI Imaging? What are the Working Principles?

What is MRI?

Magnetic resonance imaging, or MRI, is a non-invasive medical imaging tool that produces detailed images of almost every internal structure in the human body, including organs, bones, muscles, and blood vessels. MRI scanners, It creates images of the body using a large magnet and radio waves. Unlike X-rays, no ionizing radiation is produced during an MRI examination. These images are important information to your doctor in diagnosing your medical condition and planning the treatment process. gives.

How does an MRI scan work?

An MRI machine is a large, cylindrical (tube-shaped) machine that creates a strong magnetic field around the patient and sends pulses of radio waves through the scanner. Some MRI machines resemble narrow tunnels, while others are more open.

The strong magnetic field created by the MRI scanner causes the atoms in your body to align in the same direction. Radio waves are then sent from the MRI machine and these atoms move out of their original positions. Radio When the waves are turned off, the atoms return to their original positions and send back radio signals. These signals are received by a computer and converted into an image of the body part being examined. This image appears on a viewing monitor.

Computed tomography (  BT ) ._11100000-0000-0000 -0000-000000000111_MRI is better at telling the difference between soft tissue types and between normal and abnormal soft tissues.

Since no ionizing radiation is used, there is no risk of radiation exposure during the MRI procedure.

More recent uses of MRI have contributed to the development of additional magnetic resonance technology. Magnetic resonance angiography (MRA), is a procedure used to evaluate blood flow in the arteries. MRA is also aneurysms and vascular malformations in the brain (brain, spinal cord) or abnormalities of blood vessels in other parts of the body.

Functional magnetic resonance imaging (fMRI) of the brain is used to determine the specific location in the brain where a particular function, such as speech or memory, occurs. The general areas of the brain where such functions occur are known, but the exact location may vary from person to person. . During fMRI of the brain, you will be asked to perform a specific task, such as reciting the Pledge of Allegiance. By determining the exact location of the functional center in the brain, doctors surgery or other treatments for the disorder They can plan.

How can I prepare for an MRI procedure?

EATING/DRINKING:  As with most MRI examinations, you can eat, drink, and take medication._11100000-0000-00 00-0000- 000000000111_There are some special MRI exams that require certain restrictions. Detailed preparation instructions will be provided to you by Johns Hopkins Medical Imaging when you schedule your exam.

CLOTHING: Remove all clothing, including underwear _11100000-0000-0000-0000-0 00000000111_and locking up all your personal belongings_11100000-0000-0000 -0000-000000000111_you will be asked . Please remove all your piercings and leave all your jewelry and valuables at home.

EXPECT: Imaging occurs inside a large, tube-like structure that is open at both ends. Totally still for quality images You should go to bed. Due to the loud noise of the MRI machine, earplugs are required and will be provided.

ALLERGY : Some MRI exams require IV contrast. If you have had an allergic reaction to MRI contrast, contact your ordering physician to obtain the recommended prescription. contact. You will probably take this orally 24, 12 and two hours before the examination.

ANXIETY MEDICATION: If you need anti-anxiety medication for claustrophobia, contact your ordering doctor for a prescription. Bring your prescription with you on the day of your appointment. required. Please note that you will need someone to take you home.

STRONG MAGNETIC ENVIRONMENT : If you have any metal in your body due to the strong magnetic field, you should inform your doctor before the appointment. Your suitability for MRI Detailed information such as type and location will be needed to determine the condition. If you have metal in your body that was not disclosed before your appointment, your study may be postponed, rescheduled, or canceled upon arrival until more information is available.

Depending on your medical condition, your healthcare provider may require other preparations.

When you call to make an appointment, it is extremely important that you inform your doctor if any of the following applies to you:

  • If you have a pacemaker or have had heart valves replaced.

  • If you have any type of implantable pump, such as an insulin pump.

  • If you have vascular stents or clips.

  • You are pregnant or think you may be pregnant.

  • If you have ever had a gunshot wound.

  • If you have ever worked with metal (for example, as a metal grinder or welder).

  • If there are metal parts anywhere on your body.

  • If you are unable to lie still for 30 to 60 minutes.

  • If you have a phobia of closed spaces.

What happens during the MRI procedure?

MRI scans may be performed as an outpatient or during your hospital stay. Although specific protocols vary between facilities, the MRI procedure generally follows this process:

  • You will be asked to remove any clothing, jewelry, glasses, hearing aids, hair clips, removable dental supplies, or other objects that may interfere with the procedure.

  • You will be given a dress to wear.

  • If a contrast procedure is to be performed, a vein will be opened in the hand or arm for the injection of contrast dye. If the contrast material will be taken orally, the contrast material will be given to you by swallowing.

  • You will lie on a scanning table that slides into the large circular opening of the scanning machine. Pillows and slings may be used to prevent movement during the procedure.

  • The technician will be in another room with browser controls.  If you encounter any problems during the process, you will have a communication ball so that you can inform the technician. The technician will always monitor you and be in constant communication.

  • You will be given earplugs or headphones to help block out noise from the scanner. Some headphones can play music.

  • During the scanning process, a clicking sound will be heard as the magnetic field is created and pulses of radio waves are sent from the scanner.

  • It will be important that you remain still during the examination, as any movement may cause image distortion and affect the quality of the scan.

  • Occasionally, you may be instructed to hold your breath or not breathe for a few seconds, depending on the body part being examined. You will then be told when you can breathe. You will be told when you can breathe for a few seconds. You don't need to hold it for longer.

  • If contrast dye is used, you may experience some effects when injected into the IV line. These effects may include a flushing or cold feeling, salty or metallic taste in the mouth, short-term headache, itching, or nausea and/or vomiting.  These effects usually last a few minutes.

  • If you experience difficulty breathing, sweating, drowsiness, or heart palpitations, you should notify the technician.

  • When the scan is complete, the table will slide out of the scanner and you will be helped to get up from the table.

  • If an IV line was placed for contrast administration, the line will be removed.

Although the MRI procedure itself does not cause pain, lying still throughout the procedure may cause some discomfort or pain, especially if you have recently had an injury or an invasive procedure such as surgery. The technician will take all comfort measures possible. will use it and complete the procedure as soon as possible.

What happens after the MRI procedure?

You should move slowly when getting up from the scanner table to avoid experiencing dizziness or dizziness from lying flat during the procedure.

If you have taken any sedatives for the procedure, you may need to rest until they wear off. You will also need to avoid driving.

If contrast dye was used during the procedure and you experience any side effects or reactions due to the contrast dye after your appointment, such as itching, swelling, rash, or difficulty breathing, call your doctor immediately. Emergency help in a life-threatening situation. call your phone.

If you notice any pain, redness, and/or swelling at the IV site after returning home, you should notify your doctor as this may indicate an infection or other type of reaction.

Otherwise, there is no need for special care after the MRI scan. You can continue your normal diet and activities unless your doctor advises you differently.

Depending on your specific situation, your doctor may give you further or alternative instructions after the procedure.


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