Understanding MRI Scans: How They Work and What to Expect

Author :-

Dr.Sreejaya

General Medicine & Diabetology

Introduction to MRI Scans

What is an MRI scan?

Radiologists use magnetic resonance imaging to image bodily anatomy and physiological processes. MRI scanners image organs using powerful magnetic fields, magnetic field gradients, and radio waves.

The Role of MRI in Modern Medicine

MRI scans detect soft tissue diseases, like tumours, including cancer. Ligament injury. Injury or sickness of joints.

How MRI Scans Work

Basics of MRI Technology: Magnetic Fields and Radio Waves

Diagnostic tests like MRI may provide comprehensive pictures of almost every human structure and organ. MRI creates computer pictures with magnets and radio waves. MRI does not use ionising radiation. MRI scans depict organs, bones, muscles, and blood vessels.

Differences Between MRI and CT Scans

CT scans gather a rapid series of X-rays, which they then combine to create images of the scanned region. MRIs employ powerful magnetic fields to image the body. Imaging generally starts with CT scans. CT scans cannot identify some disorders, while MRIs can.

Understanding MRI Images and What They Reveal

Types of MRI Scans

Functional MRI (fMRI): Imaging Brain Activity

A functional MRI scan can reveal your brain's most active regions. Tracking previous activity and comparing it to your current activity can map your brain activity. Usually used for brain surgery planning.

Magnetic Resonance Angiography (MRA): Visualising Blood Vessels

An MRA creates blood vessel pictures from an MRI. Your clinician can also employ IV contrast to improve vascular imaging. MRIs can show blood vessels, organs, or the full body.

Diffusion MRI: Studying White Matter in the Brain

Diffusion MRI is best for in vivo white matter microstructure analysis. During diffusion encoding, water molecules move on a length scale akin to biological structures.

Cardiac MRI: Imaging the Heart

Cardiovascular magnetic resonance imaging (MRI) is a non-invasive method for assessing cardiovascular function and anatomy.

Musculoskeletal MRI: Visualising Joints and Soft Tissues

MRI combines radio waves, a high magnetic field, and a computer to create detailed images of joints, soft tissues, and bones. MRI is typically more effective in testing for injuries, tumours, and degenerative diseases.

The MRI Machine: What to Expect

Components of an MRI Machine

A superconducting coil-based primary magnet, gradient coils, radiofrequency (RF) coils, and computer systems make up an MRI system. Safety concerns apply to all components.

Noise, Claustrophobia, and Patient Comfort During the Scan

Open MR scanners' 360-degree view may alleviate claustrophobia. However, modern closed MR scanners with patient-centred design (short and broad bore) and noise reduction can reduce claustrophobic feelings by up to three times.

Open MRI vs. Closed MRI: What’s the Difference?

Open and closed-bore MRIs are the major varieties. Open MRI machines may be more comfortable owing to their absence of an enclosed area, yet closed-bore MRI machines produce the best pictures.

Preparing for an MRI scan

Steps to Take Before Your MRI

Unless instructed differently, eat and take your medications before an MRI. Most magnetic imaging procedures require that you wear a gown and remove anything that might disrupt the scan, such as jewellery.

What to Wear and Bring to the Appointment

Remove hair clips, jewellery, watches, hearing aids, and metal dentures. Make sure to wipe your credit cards before going to an MRI. Exams require a gown. Describe claustrophobia to your doctor and MRI technologist.

Considerations for Patients with Implants or Metal Objects

MRIs won't harm metal implants like hip and knee replacements that are well-secured to your bone. Metal won't heat up or move during an MRI. If metal is near an organ like the prostate, visual distortion may occur.

Is MRI harmful? Safety and risk

Understanding MRI Safety: Radiation-Free Imaging

An MRI uses no radiation, so there is no risk. Patients with pacemakers cannot undergo MRI owing to the intense magnet.

Potential risks and precautions for MRI scans

Time-changing magnetic fields make loud pounding noises that can damage hearing without ear protection. A twitching feeling may result from peripheral muscle or nerve activation. The MRI scan's radiofrequency radiation may heat the body.

MRI Scans During Pregnancy: Is it Safe?

In the second and third trimesters, an MRI is safe for the fetus. It is advisable to consult radiology faculty before undergoing a first-trimester MRI. A lactating patient can continue breastfeeding after receiving iodinated contrast or gadolinium.

The MRI Process: Step-by-Step Guide

From check-in to scan completion: what happens during the scan?

Expect the following after your MRI check-in: Radiology professionals check identification and exam requests. Please change into a hospital gown, trousers, robe, and socks and put your stuff in a locker.

How Long an MRI Takes and What Happens After

Scan time might be seconds, or 3–8 minutes. In brief scans, you may hold your breath. The area and number of pictures determine the scan time, which is 15 to 90 minutes.

Common uses of MRI scans in diagnosis

MRI is used to diagnose disorders of the brain and nervous system.

Doctors can use a brain MRI to detect bleeding, edema, brain development issues, tumours, infections, inflammation, injury, stroke, and blood vessel issues. Doctors can use the MRI to diagnose headaches and seizures.

MRIs for musculoskeletal issues

MRI can reveal high-resolution anatomy pictures with unmatched tissue contrast noninvasively. For soft tissue failures such as meniscal, ligament, and tendon rips and occult bone injuries, MRI is the dominant imaging tool.

MRI for heart, blood vessels, and organ health.

A cardiac MRI uses radio waves and magnets to produce pictures without physically entering your body. A cardiac MRI can reveal the health of your heart, including chambers, valves, and muscles, as well as blood flow.

Conclusion

Any problem could occur at any point in time. Hence, to pursue a thorough health investigation, an MRI is done. However, Ovum Hospitals has such amenities to cater to the best possible healthcare service. To know more, visit Ovum Hospitals.

FAQs

1:Can an MRI identify all cardiac issues?

MRI can diagnose cardiovascular anatomical anomalies (e.g., congenital heart defects), functional abnormalities (e.g., valve failure), tumours, and coronary artery disease and cardiomyopathy.

2: Does an MRI indicate blood vessel damage?

MRI, ultrasonography, and CT scans identify many vascular abnormalities. These tests let clinicians see impacted and surrounding blood vessel structures.

3: Is MRI or CT superior for blood vessels?

We use CT scans to diagnose the following conditions: Problems with circulation: CT scans detect heart disease, blood vessel blockages, renal issues, pulmonary oedemas, and aortic aneurysms.

4: What are two main MRI drawbacks?

Magnetic fields shift over time, making loud pounding noises that can damage hearing without ear protection. They may stimulate peripheral muscles or nerves, causing twitching. MRI scans may heat the body due to the use of radiofrequency radiation.

5: What replaces an MRI?

A CT scan may be advised if an MRI isn't possible. Due to the MRI's intense magnet, those with metal implants, pacemakers, or other devices shouldn't have one. CT scans show bones and soft tissues.