Can differences in CT scan technology impact lung scan results - 1248415

jgnindyrr
Posts:3

Ten years ago I had a lung scan that detected two nodules. One was calcified. The other nodule was 2 mm in size and was non-calficied. My physician reviewed and said not to worry. Probably histoplasmosis, which is common here in Indy.

Just last month, due to family concerns, I had another lung scan. This one revealed one calcified nodule and a total of five non-calcified nodules. These non-calcified nodules range from less than 1 mm to 4 mm. I am concerned that I now have more nodules and one is apparently larger after ten years.

I will be seeing my family MD about this.

My questions:

Could changes in CT scan technology be all or partially responsible for the different results?

Will the newer machines pick up more nodules?

Could the old 2 mm nodule simply appear larger due to changes in technology?

I am not sure of the specifications of either scanner, but I assume much has changed in ten years.

Thank you.

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Reply # - September 26, 2012, 12:41 PM

catdander
Posts:

Your assumptions are right on. With newer higher resolution imagery it is common to pick up more. I'll look around for references to substantiate this non medical professional.

Also it's very common to find non malignant lesions in the lung and it's also very common to worry about them. I hope you can live a long life of not so worrisome watch.

Janine
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Reply # - September 26, 2012, 09:09 PM

Dr West
Posts: 4735

Here's a podcast that covers all of these issues very well.

http://cancergrace.org/lung/2011/12/07/yankelevitz-lung-nodules-podcast/

The key conclusion is that the technology is so good, the sensitivity to detect nodules now so high, that just about anyone can be found to have lung nodules. There is also some variability in how large nodules are, so that 1-2 mm is within the range of error.

Finally, I'd say that if a nodule grew to just 2 mm over a decade, that is so extremely slow that it is hard to imagine that would be a realistically threatening cancer.

-Dr. West

Reply # - September 27, 2012, 12:46 PM

jgnindyrr
Posts: 3

Thanks so much to Janine and Dr. West for these responses.

I apologize in advance for posting again, but I have some new information from my internal medicine MD.

He reviewed the recent scan results and compared them to my scan results of ten years ago. On the old scan, there was a 2 mm non-calcified nodule in the right lung. I had assumed that this 2 mm nodule had grown over ten years and now was the 4 mm non-calcified nodule reported on my current scan. Turns out I had the locations wrong; my MD says I have a calcified nodule in my right lung. So he believes the 2 mm nodule in my right lung calcified over the past ten years.

But the current report indicates I also have five nodules ranging in size from less than 1 mm to 4 mm. I thought that some of these non-calcificified nodules might have been present ten years ago, but simply not picked up due to technology. But how could the old scan have missed the larger one?

My MD says these nodules are common, and he would typically do a follow up scan in 9-12 months. He also offered to refer me to a specialist, an offer I accepted.

But I remain confused about the differences in scans.

Could the differences still be due to technology?

I also understand that histoplasmosis can cause nodules, but I thought this was a one-time issue. Or could another exposure to histoplasmosis cause more nodules?

Thank you for your help and this very useful forum.

Reply # - September 27, 2012, 05:20 PM

Dr West
Posts: 4735

Nodules can also occur from inflammation or infection, so it's really possible that something new did appear in the last 10 years without it being from cancer. Histoplasmosis, for instance, can potentially lead to new nodules over time. It sounds very reasonable to follow these findings over time to look for interval change. In general, if things don't change over a period of a couple of years, it's extremely likely that the lesions are benign.

-Dr. West

Reply # - October 2, 2012, 06:30 AM

catdander
Posts:

I can imagine your wanting to know though there is no way of saying what it may be without watching it over time. It's called the wait and watch approach, we all have to do it here, and drives us all a bit off balance to put it mildly.
I will assume/hope for you that it is a fleeting infection that is already resolved. And I know you will worry no matter what...but remember most people have them they just don't have scans.
All the best,
Janine

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