All MRIs Are Not Created Equal
Low-quality images and readings by nonspecialized docs contribute to misreads.
Jan. 25, 2009 -- The pain in Katie Vincent's leg was so severe, she begged doctors to give her an MRI. It began in December 2007. She visited the urgent care in her hometown of Longview, Wash., north of Portland, Oregon. Each time, she was sent home with painkillers, which provided little relief.
"It was just constant," said Katie. "It didn't matter whether I was sitting, laying, not even on my leg, it was just a throbbing, achy horrible pain."
Doctors told her it was probably a ski injury, and that since she was only 24 years old, it would likely improve. When it didn't, Katie limped back to the hospital on crutches, to beg someone to give her an MRI. They finally agreed to do the scan, however Katie and her family were shocked to learn that the reading came back normal.
Maxine Vincent, Katie's mother, was in the room. "I couldn't believe they were saying it's normal because I know her. She's really strong, and she couldn't function. "
Dictation on the MRI showed a normal reading, and the doctor there suggested she see an orthopedist. However, getting an appointment when she had a normal reading on her MRI proved to be very difficult. Most doctors wanted her to wait weeks.
But Dr. John Kretzler, an orthopedist with the Pacific Surgical Institute in Longview, agreed to see her. He knew immediately that her MRI was anything but normal. "The initial reading of the MRI made no comment as to whether there was an abnormality in her femur," Kretzler said. "I wasn't comfortable with the way it looked. With her pain and the way she was presenting, I thought something was going on. I was surprised there was no comment as to what the bone looked like." Katie said when Dr. Kretzler touched her leg with the littlest amount of pressure, she nearly jumped off the table. Kretzler informed her that her MRI was misread.
"He threw out a bunch of words like lymphoma, benign tumor," said Katie. "And to know they missed it, it was a horrible feeling."
While Katie finally had a sense of what might be wrong, she ran into another roadblock. Before she could see a cancer specialist recommended by Kretzler, she first had to undo the faulty MRI reading. Her insurance company was unwilling to cover further treatment, until the MRI dictation was changed.
When she finally made it to a cancer specialist, she learned she had non-Hodgkins lymphoma. She spent the summer in and out of the hospital, having chemo and radiation. Knowing that the growing cancer could have been missed if her pain had subsided made her angry.
"I could have gone months or years and it would have gone to a stage four and been horrible," she said.
"Good Morning America" had Dr. William Bradley, one of the country's top radiologists and chairman of radiology at UC-San Diego, look at Katie's MRIs.
"I've seen subtle abnormalities missed, but I have never seen anything this obvious missed," said Bradley. "If she had just stopped with a quote, normal reading, and nothing further would have happened on this, she would have died."
Doctors at academic hospitals around the country report that misread MRIs are all too common.
Dr. Vivian Lee is president of the International Society for Magnetic Resonance. The society is one of the premier groups in the world dedicated to the development and clinical application of MRI technology. "It's very common that we are asked to look at another set of images," says Lee. "Frequently our surgeons and our other physicians will bring us images to reinterpret. They may want an affirmation that what was interpreted from another center was correct, or they may have doubts because there were inconsistencies between what was interpreted and what the patient is experiencing."
One problem doctors mention: radiology groups where the physicians are more generalists than specialists. "One day they are doing MRI, one day they are doing mammography, one day they're doing angiography, ultra sound, CT, they do everything, but it's the old Jack of All Trades, master of none, " said Bradley.
Radiologists with focused training in one area of the body make them more sensitive to the nuances in the scans.
"You do have some benefits I think to going to somebody who is subspecialty trained," said Lee. "That ability to be able to concentrate on specific pathologies, I think is very important in terms of being the best at interpreting those images."
For most radiologists, this multi-year specialty training begins after medical school. Others who attended medical school years ago, can follow up with continuing education courses in their specialty.
But it's not only the skill of the radiologist that guarantees a correct diagnosis. It's also the quality of the image. The stronger the magnet, the better the picture. The measure for field strength in MRI machines is called the tesla. The lower the tesla or magnetic field strength, the less clear the image.
Dr. Paul Finn, director of magnetic resonance research at the David Geffen School of Medicine at UCLA, explains not every machine is equal.
"Some are outstanding, some are not," says Finn. "Interpretation of poor-quality studies can be very difficult, even for some competent interpreters. I'm sure most patients and many physicians don't realize there is such variability. It's a complex field."
3T or 3 tesla MRI machines are the gold standard in terms of picture quality. They are more common in academic settings, but are used for regular patients as well.
And those open MRI machines, which have become especially popular for patients who are claustrophobic, are rarely high-tesla magnets. In most cases, their images are not nearly as good, according to the doctors we spoke with. They recommended patients try some kind of sedation to make the closed tube-like magnet bearable.
The American College of Radiology accredits MRI facilities around the country to be sure they are up to current standards. But that accreditation isn't mandatory, so not every location has the ACR stamp of approval. At last count, there were more than 7,000 MRI facilities nationwide, with more than 4,800 accredited by the college. That leaves over 2,000 sites unchecked by the ACR.
"It is scary. So you really should kind of shop around if you're a consumer," says Bradley.
What You Should Ask Your Doc About Your MRI
According to Dr. John Mazziota, professor of nuclear medicine and imaging at UCLA's School of Medicine and director of their Brain Mapping Center, there are several questions patients ought to ask to ensure they will have better chances of getting an accurate diagnosis.
How well-trained is the radiologist reading the MRI?
Is the doctor sub-specialized, fellowship trained, in the area of the body your MRI is for? If you don't feel good about the radiologist's background, you could always have your images sent via mail, email or on CD to a more specialized doctor in another place.
What kind of MRI machine will the scan be done on?
It is important to know whether the machine is accreditted by the American College of Radiology. Find out the strength of the magnet and ask if it is enough to make a clear scan.
Some problems will require higher resolution scans to be identified so make sure the MRI you go to has a good chance of showing clear results.
Check with your doctor before deciding on an open MRI.
Those open MRIs that have become so popular are rarely high-tesla magnets. Their images are not nearly as good. Several doctors recommend patients try some kind of sedation to make the closed tube-like magnet bearable if claustrophobia is a concern in a normal MRI.
Additional Tips
Ask About the Radiologist Who Is Reading Your MRI.
Is the doctor sub-specialized and fellowship-trained in the area of the body your MRI is for? If you don't feel good about the radiologist's background, you could always have your images sent via mail, e-mail or on CD to a more specialized doctor.
Ask What Information the Doctor Is After.
What are you expecting to find or rule out by having an MRI?
Ask About the Kind of MRI Machine. Is the machine ACR accredited?
What is the tesla or magnetic strength of the machine? For some scans, you need a newer, more advanced machine. You need to ask the doctor if the place you are being sent for the scan has an MRI machine that can offer a high-quality answer to that question.
If You Are Considering an Open MRI, Perhaps Because You Are Claustrophobic, Check With Your Doctor.
Those open MRIs which have become so popular are rarely high-tesla magnets. The images they produce are not nearly as good. So the doctors we spoke with recommended that patients try some kind of sedation to make the closed tube-like magnet bearable.
For more information on MRI's go to Radiology Info, sponsored by ACR and the Radiological Society of North America, at radiologyinfo.org and the International Society for Magnetic Resonance in Medicine's web site at ismrm.org.