Scans and X-rays
What Does Hypodense Mean on a CT Scan?
Hypodense · say it: HY-poh-denseAlso written: low attenuation, low density
Short answer
Hypodense is a CT scan word for an area that looks darker than the tissue around it because it blocks fewer X-rays.
What it means
CT scans use X-rays to build pictures. Tissues that let more X-rays through look darker, and tissues that block more look brighter.
Hypodense means an area looks darker than its surroundings on CT. Fluid, fat, air and some kinds of tissue changes can look hypodense.
It is a description of appearance, not a diagnosis. Radiologists combine it with size, shape and other features to suggest what the area might be.
Where you may see it
- CT scan reports of the head, chest, abdomen and pelvis
📄 How it looks on a report
A small hypodense lesion in the liver, too small to characterise.
🙅 What it does not mean
- It does not mean something is wrong. Many hypodense areas are harmless, such as simple cysts.
- "Too small to characterise" does not mean it is worrying. It just means the scan cannot show enough detail.
- It is not the same as hypoechoic, which is an ultrasound word.
🎯 Check yourself
Which of these is the right meaning of “Hypodense”?
🗒️ Questions to ask your doctor
🧾 Reports where you will see “Hypodense”
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🔗 Read more from trusted sources
- “Hypodense” on MedlinePlus ↗
US National Library of Medicine
- RadiologyInfo.org ↗
Radiological Society of North America and American College of Radiology
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More words: scans and x-rays
General information about a medical word, not advice about your own results. Ask the clinician who ordered the test what it means for you.