Partial volume averaging
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
When one slice contains two different tissues, the scanner reports their average, which can invent an appearance belonging to neither. It is why a thin slice through the edge of a structure sometimes suggests something that thinner slices show is not there.
Where you’ll see this
CT and MRI findings, offered as the innocent explanation for a borderline appearance.
Your report may word it “Volume averaging” or “Partial volume effect”. These mean the same thing.
Questions worth asking your doctor
- Was any part of the scan unreadable because of this?
- Does it need to be repeated, and if so how soon?
- Could this have hidden something, or only made the pictures look odd?
Picture problems, not body problems
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