MRIs in Medicine - Essay Example

There are many questions that are of common discussion in the field of medicine, and one particular subject of interest in this field is that of MRIs. In order to better understand this subject matter, we must address the following questions:

1. What is an MRI?
2. What use is each of these best for MRI, X-Ray, CT Scan?
3. Why would an MRI be ordered for a patient?
4. What would not be an appropriate situation for an MRI not to be done?
5. Are there any limitations on an MRI?
6. What are the risks involved with an MRI?

By discussing these six questions, we can come to a clearer and more understanding view on the matter of MRIs and their relative subject interest.

What is an MRI?

An MRI (Magnetic Resonance Imaging) is a non-invasive method of obtaining images of one’s internal soft bodily tissue such as the brain or the spinal cord through the use of a combination of a large magnet, and radio frequencies. In more specific terms, an MRI is “…a diagnostic technique based on the analysis of the absorption and transmission of high-frequency radio waves by the water molecules in tissues placed in a strong magnetic field. Using computers this analysis can be used to produce images of the tissues in any place of the body.” (“BBC”, 2006).

What use is Each of These Best for: MRI, X-Ray, CT Scan?

An MRI is best and therefore understandably most used for imaging soft tissue.

An X-Ray is also used to image internal structures of the body, but as opposed to an MRI, an X-Ray is a type of high-energy radiation. X-Rays are made of electromagnetic radiation with wavelengths between ultraviolet and gamma rays and are most often used in low doses for making images of internal body structures and in higher doses for treating cancer.

A CT Scan (CAT Scan) is again, another form of viewing the internal structures of a person’s body. CT Scans are in fact a computerized series of X-Rays, which can reveal tumors and small strokes in the brain. A computer is used to generate a three-dimensional image, which is then analyzed and displayed for diagnostic purposes.

Why Would an MRI be Ordered for a Patient?

An MRI is most often used for studying nerves, muscles, ligaments, bones, and other tissues in the body. Problems such as disc herniation in the spine or masses or tumors within soft tissues are seen well on an MRI image. MRIs are most helpful and most commonly used by orthopedic surgeons; an MRI is particularly helpful in diagnosing many common orthopedic problems. Therefore the most probable explanation as to why an MRI would be ordered is if orthopedic problems are perceived to exist in a patient.

What Would it be an Appropriate Situation for an MRI not to be Done?

There are several proper explanations for why an MRI would not be ordered for a patient. Firstly, an MRI is not the most accurate test. Although an MRI is useful in the diagnosis of many conditions, it is not 100% accurate in all cases, which means sometimes the problem will not show up in the MRI. Another primary reason why an MRI might not be ordered is that an MRI is usually “…not the first step.” (Cluett, 2006). In other words, there are other steps that should be taken in an attempt to figure out the problem, rather than immediately ordering an MRI. Last but certainly no less important, is the fact that an MRI is only a diagnostic test and not a treatment. “An MRI gives some people peace of mind, but will do nothing to change the symptoms of your condition.” (Cluett, 2006).

Are There Any Limitations on an MRI?

Although MRIs have major technological advantages when compared to other imaging modalities, there are also certain limitations that are present. Disadvantages are there, such as the fact that because of the small bore of the magnet, some patients experience claustrophobia and often have difficulty cooperating in the study. As well, some obese patients cannot be studied by an MRI. Patient throughput is also slower than comparative imaging modalities. Another limitation of an MRI is that patients with pacemakers or certain ferromagnetic appliances cannot be studied.

What are the Risks Involved With an MRI?

MRI imaging is based on the magnetic property of atoms, unlike conventional radiography and computed tomographic (CT) imaging, which makes use of potentially harmful radiation. An MRI is instead a painless radiology procedure and there are no known side effects of the scan. However, because the MRI scanner is a large magnet, it is therefore incredibly important to notify the technologist of metal implants and it is necessary to remove all metal objects such as keys and watches before even entering the scan room. The only other – and still relatively minor in basic aspects – chance of risk is due to the injection of a contrast material, which may be required by some MRI exams. The most common contrast used is called gadolinium – which basically does the same thing for an MRI as iodine does for CT Scans – and the complication rate for this is very low.