Progression
Read Your Scan Editorial Team·Last updated
Written from published radiology references and reviewed for plain language. Not written or signed by a physician, and not a diagnosis. How we write these pages →
In plain language
Something has grown, spread or increased since the last scan. It is a description of movement over time, and how much it matters depends entirely on what the thing is — your doctor puts that number in context.
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Where you'll see this
Follow-up impressions, often with a measurement then and now.
Your report may word it “Interval progression”, “Increased” or “Interval increase”. These mean the same thing.
Questions worth asking your doctor
- Compared with my last scan, is this better, worse, or the same?
- How much change would matter enough to do something about it?
- When should the next scan be, and what would you be looking for?
How often does this turn up?
Progression means something has advanced since the previous scan — grown, spread, or increased. It belongs to the comparison vocabulary along with stable, unchanged, resolved and regression, and it appears wherever a finding is being followed over time.
Does it mean something is wrong?
This is a word that means what it says, and its weight depends entirely on what is progressing. Progression of degenerative changes in a spine over several years is expected and usually needs nothing. Progression of a lesion under surveillance is the finding those scans exist to catch, and it is what changes management. The report should specify what has progressed and by how much, because both matter — many surveillance protocols define in advance the amount of change that triggers action.
What to do with it
What follows is determined by what is progressing and by the protocol it is being followed under. For degenerative findings, generally nothing beyond what symptoms warrant. For something under active surveillance, progression typically prompts the next step in a pathway that was already planned — a shorter interval, a different scan, a specialist discussion, or treatment.
Frequently asked questions
- Does progression always mean things are getting worse?
- It means the finding has advanced since the last scan. Whether that matters depends entirely on what it is: progression of ordinary wear over years is expected, whereas progression of something being watched is significant by design.
- What is the opposite of progression?
- Regression, meaning it has reduced, or resolved, meaning it has gone entirely. Between them sit stable and unchanged, meaning it looks the same as before.
- How much progression is significant?
- That is usually defined in advance by whichever protocol the finding is being followed under, precisely so the decision is not made ad hoc. The report generally states the measurements so the comparison can be made objectively.
Comparison with an earlier scan
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