Magnetic resonance imaging is the preferred method of acquiring scans of the brain and the brain stem. The reason for this is that unlike CAT [computed axial tomography scans], MRI scans do not use radiation, and rely on a magnetic field and radio waves to produce images. MRI scans are found in hospitals and clinics throughout the world and are used for a number of reasons.
MRI machines consist of large, doughnut-shaped magnets that have tunnels in the middle. Patients waiting for a scan are placed on a sliding table, occasionally anesthetised, and slid into the tunnel to have their scan taken. Some hospitals and clinics have machines which have larger openings, and these are most often used for patients who suffer from claustrophobia and cannot bear the forty-five-minute wait time.
This page will hope to tell you what we can learn from MRI scans, how the scans are taken [in more detail than has already been offered], and why someone might need an MRI scan. Generally, MRI scans come without complication and side-effects, so you have nothing to worry about if you are preparing to go in for one.
So, you want to know what can be learnt from an MRI scan? Let’s find out then, shall we?
What is an MRI Machine?
Before moving onto what we can learn from an MRI scan, let’s first discuss the components of MRI machines, and what they are. MRI machines are composed of the rolling patient table, which we have previously mentioned, a large, doughnut-shaped magnet, also mentioned, a scanner, gradient coils, and a radiofrequency coil. All of these components are essential parts of an MRI machine. If you are going in for an MRI scan and are concerned about the safety of these machine’s, then you needn’t be, for when hospitals and centres are buying parts, they are sourced from the most respected and trusted manufacturers and retailers who ensure quality. MRI machines also produce high-quality [sometimes 3D] images of the body that they are scanning.
How Do MRI Scans Work?
MRI scans work by utilizing the powerful doughnut-shaped magnet, and computerized radio waves to create detailed, three-dimensional images of your body. In your body, you have magnetic water molecules. When placed inside a magnetic field, these molecules align with the field, in the same way, that a compass points toward the North Pole. Radio waves then disrupt the polarity of these molecules. The sensor built into the MRI scan uses this disruption to measure the time it takes for the molecules to return to the original alignment, which then produces images. Simplified, MRI scans measure the water content of tissues in your body, which is then processed to create a detailed image of the organ. These images are very detailed and can show the tiniest of problems or abnormalities.
Occasionally, a dye is introduced to the body through an intravenous line to enhance the imagery of some tissues. The dye has magnetic properties, and circulates through the bloodstream, allowing certain areas to stand out on the scan so doctors can better examine them. This contrast dye is also used to see tumors and abnormalities.
What Can We Learn from an MRI Scan?
We can learn many things about our bodies from an MRI scan, as MRI scans provide very detailed, intricate images of soft tissues like your brain. Hard bone and air do not give MRI signals, so in a scan, these areas will appear black. Spinal fluid, blood, and soft tissues vary in intensity from white to black, depending on the amount of fat and water that is present at the time of the scan. A radiologist will comparatively look between these white and black patches to establish the health of a tissue or organ.
- Head and neck scans – Head and neck scans are used to detect abnormalities in the brain, such as tumours or traumatic injuries; developmental anomalies; multiple sclerosis; dementia; infection; stroke, and the causes of migraines and headaches;
- Arteries and veins – Arteries and veins are scanned to check for aneurysms, blockages, and carotid artery disease;
- Spinal scans – Spinal scans are used to detect any changes or abnormalities in cartilage and bone structure which may stem from injury, ageing, or disease. Spinal scans also detect herniated discs, spinal tumours, pinched nerves, tumours, cord compressions, and fractures.
Preparation for an MRI Scan
If you are due an MRI scan, and that is why you are reading this. You should prepare for your scan by:
- Avoiding drinks with high sugar content and caffeine;
- Dress comfortably, as you will have to lie down for up to half an hour [sometimes more];
- Bring insurance documentation;
- Bring relevant X-ray, MRI, or CT documentation;
- Do not wear anything metallic.
- Have a family member to take you home; in rare cases, people feel dizzy afterwards.
With the help of this page, you should now understand what we can learn from an MRI scan. MRI scans are a very important part of the healthcare industry, and without them, we would have to rely on surgical procedures. We hope this page was of benefit to you, for whatever purpose you read it.