Moderated by Jeffrey R. Carlson, MD
How is an MR scan different from a CT scan?
An MR scan uses a large electromagnet to image structures and soft tissues. It does so by creating a magnetic field and using computer generated radio waves to image water molecules in the part of the body being scanned. This scan is used when structures other than bone need to be visualized in detail by physicians to make a diagnosis. A MR scan is expensive, takes at least 30 minutes to an hour to complete and must be read by a Radiologist. The patient must lie very still during the test and may experience claustrophobia inside a small-bore MR scanner. It is painless; however, some patients find lying still to be very painful or even impossible. Contrast dye may or may not be used based on the suspected diagnosis. Persons who have certain metal implants, shrapnel, shunts, pacemakers, pumps, etc. may not have an MR scan due to the magnet’s strength and the possibility of movement of these articles in the body.
An X-ray shoots radioactive waves through the body onto an imaging “plate”. The waves cannot pass through human bone, so they leave a converse image of the bone on the “plate”. Nowadays, this is all done digitally, and no x-ray film is used. X-ray is the gold standard for imaging bone and for diagnosing fractures, bone spurs, arthritis, etc. It doesn’t image the other structures of the body as well as an MR or CT scan. It is painless, however exposure to radiation must be limited for the patient’s safety. This diagnostic test is the least expensive of the three discussed here.
A CT scan is a specialized type of x-ray that uses computer tomography and a series of x-ray images to create 3-D images of structures and soft tissues inside the human body. It provides much greater detail to the physician than a regular x-ray. It is a relatively quick and painless test that can be performed, with or without contrast. Patients who cannot have an MR scan will often be sent for a CT scan. While costly, the CT is not as expensive as an MR scan, and still requires that a Radiologist read the results.
The CT scanner looks like a big doughnut that has a table that goes through the middle of it. Once the patient is positioned on the table, the “doughnut” ring will take multiple x-rays of the patient from all angles while the patient passes through the center on the table. Then the computer “laces” all the images together for the Radiologist to view. The test usually takes only minutes to perform.
I’m claustrophobic and fearful about having an MR scan. What can be done to help me?
We understand that some of our patients have a real problem with claustrophobia, and the thought of lying still in an enclosed space, even our open MRI, makes them cringe. All our Orthopaedic and Interventional Pain Management Physicians who order MR scans can prescribe sedatives for patients who have anxiety before their scheduled MR appointment. Our caring staff is well-trained to help anxious patient feel comfortable, by providing music, blankets, pillows, talking to the patient throughout the test, etc. We’ll do everything possible to help our patients comfortably and successfully complete their scan.
I have a painful back and can’t lie still for very long. I’m told I need an MRI. What can be done to help me get through the test?
We do treat patients that have a very hard time lying still, either from a painful condition they have, or from a nerve problem that causes them to move, like Parkinson’s or Restless Leg Syndrome. Again, OSC Physicians can prescribe sedatives or other medications to assist with pain, excess movement or tremors during the test. We can also provide extra weighting, padding and support for the body part being scanned that makes it more comfortable to lie still and/or acts as a reminder not to move. Our staff will work with the patient to provide comfortable positioning, padding and assistive support whenever possible during the test.
Call (757) 596-1900 to schedule an appointment with OSC. Visit our Contact Us page for information on office hours. Our office is located in Newport News, VA. We are 40 minutes from Virginia Beach and an hour from Richmond, VA.