Question your MRI comparison results

[Ted A]

Hello Everyone:

I posted here a few times over a year ago, and have been on watch-and-wait status since 2005. I would like to share my recent findings so that no one takes anything for granted, particularly the opinion of some medial professionals. Lesson 2 is particularly relevant to those watching and waiting.

Lesson 1. In 2005, two ENTs noted my asymmetric hearing loss and tinnitus, and neither suspected AN. I insisted on an MRI to be sure, which proved up the AN diagnosis. My lesson: See a specialist (otolaryngologist) at a research hospital. I suspect if you are already visiting this discussion forum, the diagnosis has been made, but advise a friend.

Lesson 2. I have had 3 follow-up MRIs since diagnosis in 2005. Each time, the radiologist was asked to compare the results to previous MRI imaging in order to monitor the AN size. Each time, the result came back with “no change in size� (twice at Methodist Hospital in Houston, and once at Mt Elizabeth Hospital in Singapore). During the last visit with my neurosurgeon (Jan 2008), we both agreed that the AN looked larger. He recently sent all 4 MRIs to a radiology specialist (someone he trusted) at the University of Chicago. The results (4 measurements over 3 years) indicated steady growth, and an increase in size of 40%. Initial size was 1.6 cm, now it is 2.2cm. This obviously could have impacted my treatment options and timing. My Lesson: Find a trusted radiologist to monitor the size of your AN. My neurosurgeon admitted that there are endemic problems in the radiology profession.

My experiences are by no means a template for typical AN behavior, or for the quality of medical professionals. But everyone owes it to themselves to double check results, and get second opinions, on doctors and radiologists.

Best of luck,
TedA

[HeadCase2]

Ted,
  Excellent suggestions.  I also think it's a good idea to have your Neurosurgeon or Otolaryngologist review each MRI as they happen.  With their background in treating AN, they can have a more informed opinion on the MRI results.  Your An looks like it's growing at the "normal" average rate of 2 mm per year.
  I like to have my own copies of the MRIs.  But then I'm a technical person and like to see things for myself.  Most MRI CDs have a viewer program that has a measurement tool, allowing you to "draw a line" across the AN, and it will tell you the length.
Regards,
  Rob

[NickD]

Rob,

I've used the measurement tools and here's a cautionary note.  Try measuring between common points on 2 MRI's first.  On key skull points I found 0.5 mm to 1 mm difference between MRI's.  If you are going to compare year to year you'll need to check this slight scale difference and include that in your "growth" calculation.  I just disregard comments from my wife regarding an over active ego 

 

[Brendalu]

Ted,
Thanks for sharing!  Welcome!  I am from the Houston area also.  Verying interesting stuff you are reporting!  I have another MRI Tuesday to check on the progress of my NF2.  I will be sure to check and double check.  Thanks again........
Brenda

[Jim Scott]

Ted:

Thanks for some excellent advice founded on experience.  I always advise 'newbies' here - and anyone I know undergoing any kind of diagnostic procedure - that you must be proactive with your health care.  No one wants to hear bad news (AN growth) but AN patients with radiologists missing that kind of growth are poorly served.  Unfortunately, this happens all too frequently and simply points out the need to engage a very experienced physician you can trust to spot abnormalities and the ability to question things that don't seem right, even if that means bruising a doctor's ego.  After all, you'll be the one to suffer the consequences if the doctor/radiologist misses something critical, such as steady growth of an acoustic neuroma, which should have been noticed

I hope this situation ultimately works out for you.

Jim

[Gloriann]

My experience was just the opposite. My neurosurgeon told me nothing was showing up on my MRI's following surgery, except scar tissue. He released me two years ago, saying I did not have to  have any more MRI's done.
One day when I was at the hospital where my MRI's were done I deceided to ask for a copy of the MRI report and was shocked to learn that there was a recurrent AN. I called my doctor right away, but he insisted it was scar tissue and was not even going to inform me of what the report said.
I saw another neurosurgeon who had me wait two years for another MRI, which was this year. He agrees with the radiologist that this is a recurrent AN which has been growing in size. Gamma Knife has been recommended to me.
I was able to talk with the other doctor who operated on me (the ear surgeon) and he agrees with the radilologist also, that this is not scar tissue, but a recurrent tumor.
A tiny piece of my tumor had to be left on my facial nerve, so it is not surprizing that it grew back.

[Ted A]

Apologies for the redundnat posting, but I think this issue needs attention.

I posted (above) about the difficulty getting consistent and objective results regarding AN size as monitored by periodic MRIs. My last post suggested that different radiologists at different hospitals came up with different interpretations of the same data. My inference was that some radiologists might be doing sloppy work.

Now I have something new to report....

My Houston otolaryngologist (Baylor College of Medicine) was curious about my assertion regarding inconsistent MRI interpretations. He took my last two MRIs and did an experiment. He measured the AN and found an increase in size. Then he measured a benchmark, a nearby organ that does not change in size. He found that the feature was different lengths in the two sets of data. My AN did not change in size as much as we originally thought. Kudos to my doctor for a simple but brilliant test. However, to put it bluntly, this sucks.

This means that different imaging technology is not consistent. There is not a reliable standard of measurement. The scale bar in the MRI image is suspect. The thing that you would expect NOT to be a variable, is. If this is a widespread problem, I would expect for there to be an occasional occurence of an AN apparently"shrinking", but I have not heard of any.

The point of periodic MRIs is to monitor the growth of the AN with time. As good as the doctors or radiologists may be, the imaging technology may prevent accurate size measurements. I am not sure if it would be hardware or a software problem.

If this kind of discrepancy is widespread, it needs to be addressed. I suggest that we encourage the ANA to approach those knowledgeable and responsible in the radiology and imaging specialty to look into this issue. The implications of this potential "negligence" are far reaching.

Doctors and patients have to be very careful making conclusions from our periodic MRIs.

Good luck,
Ted A

[mk]

I agree that there can be a lot of inconsistency in MRI results and that the radiologist reports may not be always "accurate". In my case the radiologist on my first MRI (the one used to diagnose the AN) reported a size of 2.4 cm as the maximum dimension. My subsequent MRI after 6 months showed 2.9 cm. Initially I freaked out because I thought that this was a dramatic increase in a few months time. Then I got a hold of the first MRI CD and went through the images myself. The measurements were more like 2.7 cm, and on top of this, there were very few "slices" shown on the images. I have no idea how the radiologist came up with the 2.4 cm measurement, and why none of the doctors who reviewed the MRI didn't mention that this was not the correct size  . This was really stressful, because all of a sudden I was dealing with a very very borderline size for radiation, and I had to go through all the decision process again.

Marianna

[Nancy Drew]

Just curious and hope this isn't a stupid question.  My first two MRIs were films, and the second two were on CDs.  Does it make a difference--films vs. CDs.  I am thinking the CD is newer technology.  Thanks.  Nancy