When you are ill or suffer brain injuries, it is essential for your physician to reliably and accurately see and analyze what is happening in your body. Functional magnetic resonance imaging uses powerful magnetic fields, advanced computers, and radio waves to create highly detailed images than other diagnostic methods. The immersive images allow the doctor to diagnose your health condition or monitor how you respond to the treatment.
Los Angeles Diagnostics has been offering imaging services for many years. Through patient input and experience, we recognize when you, our patient, contact us, you are in pain, anxious, and worried. Consequently, we offer an environment that is friendly and comfortable. We can also answer all your questions. We were hoping you could leave our office knowing that you are in good hands.
Introducing Functional MRI
Functional magnetic resonance imaging is a medical technique that measures brain activity. The scan detects changes in your blood flow and oxygenation following a neural activity (the most active brain area requires more oxygen, and there is more blood flow in the area). fMRI is used to get activation maps displaying what brain parts are associated with a specific mental process(es).
The development of the diagnostic method is an innovation that uses oxygen metabolism and blood flow to conclude brain activity.
fMRI has many notable advantages, including:
- It is non-invasive and does not have radiation exposure — Unlike positron emission tomography (PET), CT scans, and x-rays, there is no radiation in an MRI scan. That makes MRI safe for individuals prone to radiation effects like expectant mothers and children.
- MRI advances improve visualization — Since the introduction of MRI, its technology has constantly advanced, producing more precise and sharper images in less time. The most powerful scanners provide ultra-high magnetic fields of 7T, which can visualize your brain in unprecedented detail via enhanced contrast mechanisms. At 7T, magnetic resonance imaging improves lesion visibility and more accurately characterizes brain abnormalities. For instance, the scan can help tell where epileptic seizure stems from, visualize a brain tumor pathology, measure metabolism markers in tumor tissue, and identify neuron loss in the hippocampus in Alzheimer's disease.
- Early disease detection and diagnosis — While other diagnostic methods can sometimes prove inefficient in diagnosing specific health conditions, an fMRI can accurately detect several diseases and abnormalities even in their early stages. It helps your primary doctor to analyze and ensure that you receive the best form of treatment.
- Functional MRI is used to determine the specific brain location where a function like memory or speech happens — The general brain areas where these functions take place are known, but the exact location varies with patients. During the scan, the radiologist will request you to perform specific tasks like singing your favorite song while they conduct the examination. By identifying the exact locations of the functional center in your brain, your doctor can develop the most suitable treatment option for your condition.
These benefits have made MRI popular, particularly among psychologists and other mental health conditions practitioners. Over the years, it has offered new insights into how human beings form memories, learn, have emotions, feel pain, and their language. Additionally, fMRI can be applied in commercial and clinical settings.
Uses of fMRI
Your doctor can order the fMRI to:
- Study your brain's functional anatomy
- Determine which brain part is responsible for handling essential functions like speech, sensation, movement, and thoughts (brain mapping)
- Monitor the function and growth of brain tumors
- Assist in analysis of the impact of trauma, degenerative disease, or stroke on your brain function
- Inform the planning of radiation therapy, surgery among other brain treatments
How an fMRI Works
The MRI scanner is a cylindrical tube that hosts electromagnetic fields. Typical equipment contains a field strength of 3 Tesla's, approximately fifty thousand times more powerful than the earth's field. The magnetic fields in the MRI equipment affect the magnetic nuclei of atoms.
Typically, nuclei are casually oriented. However, after magnetic field exposure, the nuclei align in the fields' direction. The more robust the magnetic fields, the higher the alignment level. When in the one direction, the signals from each nucleus add up articulately, leading to signals that a computer can measure. In functional magnetic resonance imaging, it's the magnetic signals from hydrogen nuclei in water that the computer detects.
The signals from hydrogen nuclei vary in strength, hinging mainly on the environment. It offers a method of distinguishing between cerebral spinal fluid, white matter, and gray matter in your brains' structural images.
Hemoglobin in capillary red blood cells delivers oxygen to neurons. When neuronal activities increase, there is a direct proportion to oxygen demand, and there is an increased blood flow in the area with increased neural activities.
Hemoglobin is paramagnetic when deoxygenated and diamagnetic when oxygenated. The alteration in magnetic properties results in small variations in the MRI signals of blood hinging on the oxygenation level. Because blood oxygenation differs depending on neural activity, the variations are used to perceive brain activities.
Please note that the oxygenation's direction changes with more activity. While you would assume blood oxygenation will reduce with less activation, that is not the reality. There is a brief reduction in blood oxygenation immediately following neural activity increase in the hemodynamic response. It's followed by an increase in blood flow.
In other words, the scanner is a large cylindrical machine that creates strong magnetic fields around you. Together with magnetic fields, radio waves alter the natural alignment of the hydrogen atoms in your body. Radio waves pulses originating from the scanner knock the nuclei in the atoms out of the normal position. As the nuclei return to their original position, the nuclei send out radio signals that a computer receives. The computer analyzes and converts the signals into three-dimensional (3-D) images of the body organ or body being scanned.
Preparing for an fMRI
It is not much required as far as preparation of brain MRI is concerned. You can drink, eat, or take medication as usual. Nonetheless, suppose the physician ordered an examination for any other body part like the abdominal region. In that case, your doctor might instruct you not to eat or drink six (6) hours before your scan.
Since the scanner has magnetic fields, it can attract metals, resulting in blurry images. That is why you should remove all metallic objects before entering the examination room or leave them at home. These items include:
- Body piercings
- Jewelry
- Pens
- Hearing aids
- Hairpin
- Removable dental work
- Zippers and metallic clothing fasteners
Do not put on hair products, antiperspirants, sunscreen, nail polish, and makeup. If you use eyeglasses, you should remove them before your scan.
Before scheduling your medical appointment for the fMRI, ensure you inform your radiologist if you've one of the health conditions below:
- Kidney diseases — If you've previously suffered from kidney disease, liver disease, or kidney failure, you cannot receive gadolinium. Gadolinium is an intravenous contrast agent that increases the precision of the scan. It also increases the risk of suffering from nephrogenic systemic fibrosis, which affects organs like the skin.
- Pregnancy — Gadolinium might harm the fetus. Consequently, physicians recommend that expectant mothers should not undergo an fMRI with gadolinium during their pregnancy unless required.
- Claustrophobia (fear of being in an enclosed area) — If you are claustrophobic, you should talk to your technologist about taking anti-anxiety medications for your scan.
Other items that might pose risks to your test include:
- Artificial heart valves
- Metal plates, brain aneurysm clip, among other metal implants
- Bullet wounds
- Artificial joints
- Metal fragments
- Implantable pump
- Inner ear implant
- Pacemaker
Additionally, notify the doctor if you cannot lie for long or have previously had allergic reactions to the contrast agent that needed medical attention.
Tattoos might result in discomfort during your scan due to metallic traces in ink.
If you've worries, concerns, or questions about your medical examination preparation, do not hesitate to speak with the diagnostic facility.
What Happens During Your fMRI Scan?
Discussed below is what is involved with undergoing functional magnetic resonance imaging.
Remove Metallic Materials
The medical experts will ask you to take off and keep all your metal material in a cabinet. You can wear comfortable, loose-fitting clothes that don't have metal or a gown.
Enter the Examination Room
Your technician will escort you to the examination room that has the scanner. The equipment is a large tube with a table at the center that slides into the tube. If you have previously undergone an MRI scan, you might be anticipating a tube. Modern scanners are larger, with openings at all sides, offering more space. It makes it ideal for claustrophobic and obese patients.
Lie Down on a Scanner's Table
Next, the technician will ask you to lie on the table. Depending on your diagnostic facility, you can choose between a short-bore system or an open MRI.
A short-bore system examines only the necessary body parts and permits the remaining parts to be out of the equipment. In this case, only your upper body part will be in the MRI tube. On the other hand, all sides of the equipment are open with an open magnetic resonance imaging scanner.
Your radiologist will provide you with a foam block or pillow to ensure the head is comfortable. If you're feeling cold, you can ask the medical practitioner to cover you using a blanket.
Get Contrast Intravenous
Depending primarily on the physician's instructions, you might get a gadolinium injection before the scan to improve the images' clarity. You might feel flushing sensations or a metallic taste in the mouth following the injection. The contrast agent occasionally results in an allergic reaction.
Apart from the pinch of the needle, the contrast agent is not painful. If you are anxious about the agent, talk to the technician and inquire whether it is essential or discuss other options.
The Examination is Noisy
During your medical examination, you will hear loud clicking, thumping, and knocking sounds originating from the scanner. There is nothing to be worried about; the noises are normal. Pulses make the coils vibrate, creating loud noises.
You can use the headphones provided to you to listen to music.
Holding Your Breath
The technologist might request you to hold your breath during your fMRI scan for a couple of seconds, hinging on your test.
Should you want to halt your test or feel anxious, you could hit the call button on the scanner and speak to the physician via an intercom. Your medical expert will be in an adjacent room controlling the MRI equipment but can always see you through a window. They will also give you instructions throughout your exam, which you will hear through a speaker in the MRI scanner.
Remove the Contrast Agent
Once the medical examination is done, the radiologist will remove your contrast agent and assist you in getting out of the scanner's table. Stand up slowly to prevent feeling dizzy or lightheaded. If the physician sedates you, you should rest until the agent wears off and then have a person take you home.
Generally, an fMRI takes approximately an hour. If the doctor administered the contrast IV, the test might take longer.
How to Remain Calm During Your Examination
It would be best if you remained still and relaxed throughout your examination. It ensures that your images are accurate and precise.
As far as MRI claustrophobia and anxiety are concerned, knowledge is a powerful tool. If your primary physician ordered an fMRI, it is because they require images of your brain. The images are essential to the development of your treatment plan and your care.
Before the scan, you ought to know that some of the claustrophobia-related stories you have heard are not true. Modern scanners aren't dark and closed-off tunnels. Instead, they are open on both sides, wider, and well-lit.
However, the skilled medical team at Los Angeles Diagnostics recognizes that fMRI claustrophobia is an issue for many patients. As a result, we have compiled tricks and tips on how to remain calm during the process.
Talk to the Technician
MRI equipment is noisy. However, lines of communication between the patient and the medical technician are open. Your radiologist will give you headphones that you can use to listen and talk to one another. While the technologist will tell you what is taking place and answer all your questions, remaining relaxed sometimes requires your conversation to go a little deeper.
Make use of light moments to talk about your family or what is on your bucket list. If you cannot think of anything, discuss TV shows or the weather.
Practice Mindfulness
You can try this trick. Close your eyes and ensure tension in your jaw area and the tongue sitting on your mouth's floor. Imagine a light that radiates warmth coming into the feet. Make it go to the rest of your body.
Control Your Breathing
If you start feeling stressed after your examination has begun, try controlling your breath in a manner that will slow down your heart rate and keep you relaxed. Consider taking a long and slow inhale via your nose, holding your breath for a couple of seconds, and then blow out through your lips while relaxing your face muscles. It will force the brain to register that you aren't in danger.
Wear a Sleeping Mask
Consider wearing a sleeping mask before sliding into the scanner's bore. That way, you will not see the confined area or be tempted to look around like you would with closed eyes.
Listen to Your Favorite Music
Most scanners can play music via headphones. You can carry your music device or CD to play your favorite music. Ensure you choose a tune you find relaxing.
Bring a Loved One
Unlike other diagnostic tools, an MRI scanner does not use radiation. That means a loved one can stay with you throughout the examination, provided they do not interfere with the process. The technician should check them for magnetic materials before the scan starts and only enter the room with the radiologist's approval.
What Occurs After the Scan
Unless the doctor advises otherwise, you can continue with the daily routine and eat and drink normally. In other words, there isn't any special care needed following the examination.
Meanwhile, the radiologist will examine the scan's results and discuss them with your primary doctors. You can ask the technologist the duration it will take to hear from your physician about your results.
Should you notice redness, pain, or swelling at your IV site, notify your doctor immediately. It could be an indication of infection or reaction. Moreover, you might experience discomfort from lying still during your scan, especially if you recently had injuries or a surgical procedure. Ensure you discuss with your technologist beforehand; they'll do whatever it takes to lower the discomfort.
What the fMRI Shows
By analyzing the MRI images, the radiologist can tell the details of fluids surrounding your brain and blood flow. It assists in determining any abnormality in your brain associated with veins and arteries.
Additionally, an fMRI can show brain lesions. The brain lesions manifest as light or dark spots that don't look like normal brain tissues. They might be as a result of an infection, a tumor, or multiple sclerosis.
Generally, an fMRI will help the doctor examine the flow of blood and the health of tissues in different brain structures, including:
- Cerebellum (the brain's back) — It assists you with maintaining balance and posture. It also coordinates voluntary muscle movements.
- Brainstem (the brain's middle) — It is responsible for mouth and eye movement, hunger, consciousness, involuntary muscle movement, cardiac function, and sensory messages
- Cerebrum— Your brain's front that involves vision, touch, hearing, body temperature, movement, learning, reasoning, and emotions.
Contact a Compassionate Diagnostic Center Near Me
fMRI is an imaging technique that uses magnetic fields, radio waves, and a computer to produce detailed images of your brain. Unlike CT scans and x-rays, the sharpness of the brain images is achieved without radiation, making the procedure safe. Additionally, you don't have to change your routine or diet unless your doctor instructs you.
At Los Angeles Diagnostics, we are dedicated to offering a relaxed, convenient, and safe diagnostic center. Our experienced staff can provide incomparable customer care to ensure you are comfortable. At the same time, our medical team can deliver sharp images, interpret them, and report timely to your referring doctor for an accurate, comprehensive diagnosis. Please get in touch with us now at 323-486-7502 to schedule your appointment or for any concerns or questions.
