February 4, 2023
February 3, 2023

An introduction to Magnetic resonance imaging (MRI)

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An introduction to Magnetic resonance imaging (MRI)

Based on an interview with Dr. Charles Fiske, On-Site Radiologist and Medical Director, NorCal Imaging Walnut Creek

Magnetic resonance imaging (MRI) is a common imaging procedure that patients undergo.

How MRIs work

MRI basically creates a water map because it images the water molecule. Since most pathology is usually water-laden, MRI findings tend to be related to areas of the body with significant amounts of water (e.g., the abdomen, pelvis, and organ structures). MRIs use strong magnetic fields and radio waves to image the body without using X-rays. One important area of the body where MRI is not utilized is the lungs because of motion artifact related to breathing and minimal water is present.

Uses of MRIs

MRI can be used to image any part of the body. MRI is mostly used for imaging of the brain and spine. MRI is also useful for patients with musculoskeletal disorders; in such patients, MRIs can be used to distinguish soft issues from bony tissues.

Prepping for MRIs

Generally, no prep is needed for MRI. However, MRI patients would be well-advised to prepare themselves for potential claustrophobia. As the expansion and contraction of the coils tends to be loud, it may be advisable to bring earplugs (these are also provided at Ezra’s partner imaging facilities). Many scanners now have larger apertures (the holes that patients go into), and the length of scan time has been significantly shortened by technological advances. Managing and understanding MRI expectations can help minimize the chance of feeling claustrophobic.

Patients with implanted electrical devices such as pacemakers or artificial cochlea should be aware that these devices can be put at risk by a high magnetic field. These devices are increasingly designed to withstand MRI, but older devices may be vulnerable to damage. Additionally, shrapnel and embedded metallic devices in the body may move and possibly cause injury during an MRI exam. These need to be discussed with a medical professional before you get an MRI.

Women who are being screened for breast cancer should not be in a high estrogen-stimulated state. Ideally, women should be screened for breast cancer between menstrual cycles, as estrogen stimulates the breast tissue, which tends to obscure pathology in the breast.

Use of contrast

While most MRIs do not require the use of contrast, there are some cases where contrast (because it reflects bloodflow and vascularity) may be needed. For example, an MRI with contrast adds a physiologic component to the exam; tumors tend to have increased vascularity which can be detected with contrast.

If contrast is needed for an MRI, a gadolinium-based agent is usually used. Contrast is usually considered safe, has no immediate side effects in all but a few cases, and does not have long-term effects of significant consequence. A very small number of patients are allergic to contrast dye, but such individuals represent a very small proportion of the patient population.

How medical providers decide what to order

Medical providers can order MRIs based on a combination of their knowledge and experience, clinical guidelines and standard operating protocols, and informed clinical decision making with the patient.

Receiving and interpreting results

Imaging results are interpreted by a radiologist, and the report goes back to the ordering physician. Imaging reports tend to be full of medical jargon which may be difficult for patients to understand. However, this is changing with patient demand as patients increasingly want to understand their results themselves.

Today, there is an increasing shift toward creating reports that are simple for the patient to read and understand for themselves. The traditional pathway of interpreting the result by the radiologist and sending it to the referring doctor then having the doctor send it to the patient is changing in many ways.

This is where patient-oriented solutions like Ezra come in. Ezra’s focus on having the patient be a participant in their healthcare by understanding how the imaging fits into the big picture empowers patients to participate in their own care.

“It is increasingly clear that patients are willing to pay out of pocket to get an Ezra Scan with extra interpretation, detailed data, and longitudinal tracking of their health metrics. This shift benefits everyone. The better educated patients are about the disease processes they have and the information that imaging provides, the better-equipped they are to understand the disease processes and to be active participants in their well-being and care,” says Dr. Fiske.