In today’s New York Times Gina Kolata wrote a very interesting article about the unreliability of MRIs for diagnostic purposes. She wrote from the perspective of orthopedic injuries, but since MRIs are main stays for us suffering with prostate cancer, there is an important message for us.
Her story revolves around a running injury that she suffered. After sustaining the injury, she was given an MRI that failed to show her real, serious problem. Her MRI was taken at a local radiology center. When she went for a second opinion her orthopedist, at the Hospital for Special Surgery in New York, never saw the actual images, but only saw the written report from the center. Therefore, he ordered a new MRI at the hospital.
The second, new, MRI showed a serious stress fracture, a hairline crack in a metatarsal bone in her forefoot. The brake was so serious that her doctors told her that if she did not stay off her foot she risked needing surgery in the future to repair the injury. She also was advised to stop tasking the prescribed anti-inflammatory drugs, since they impede bone healing.
A colleague of Ms. Kolata, Jim, also at the New York Times, reported a very similar experience with a badly read MRI.
Kolata asks, “How could M.R.I.s have come to such different conclusions for both Jim and me?” They both inquired of their doctors if at the time of the initial MRIs could it be possible that neither of them had the injury that was eventually discovered? In both situations, their doctors told them the injuries most likely were present at the time of the initial MRI!
Kolata’s doctor, Dr. Kennedy explained that in her case the quality of the two different MRI images was vastly different. He compared the quality of the two images saying, “It’s like the difference between a black-and-white TV and HDTV.” Yet, the radiology center that Kolata went to is accredited by the American College of Radiology. Dr. Kennedy also reported that when she first came to him all he saw was the report written by the radiologist, not the actual pictures.
According to many academic radiologists, this problem is very common! “That’s the bane of our existence in an academic medical center,” said Dr. Howard P. Forman, a professor of diagnostic radiology at Yale University School of Medicine.
Dr. William C. Black, a professor of radiology and community and family medicine at Dartmouth Medical School stated, “That radiology centers send only written reports to doctors, so the doctors may have no idea whether the M.R.I. was done well and interpreted well. It’s a huge problem.”
Not all MRI machines are equal. There is a great difference in the machines. The differences rang from strength of the magnets to the quality of the imaging coils that surround the body. There is also a difference in the computer programs used to control the imaging and to analyze the images as well as a huge variability in skill among the technicians doing the scans.
To add to the problem, accreditation does not tell you whether your scan will be performed with a machine that is several generations old; whether the scanning is programmed to pick up your particular problem; or whether the receiving coil that picks up signals from the magnet is sufficiently sensitive.
As with many other tests, there is the question of the skill level of the radiologist who reads the scans. In many major academic centers, different readers will only read the scans in their personal area of expertise. Often at general radiological centers, generalists, without specific expertise read scans.
If it is possible, you should ask who is going to read your scan. Is it going to be a physician who specializes in the area being scanned or by a generalist?
Prostate cancer provides an additional problem for accurate MRI interpretation. Good MRIs with excellent sensitivity and expert radiological readers still cannot see small metastases. A negative MRI cannot be considered conclusive evidence of being disease free. The information provided by the scan needs to be used in conjunction with your history, how you feel and the expert opinion of your doctors.
Joel T Nowak, MA, MSW