A plain-language guide to common CT terminology found in radiology reports (no diagnosis, no interpretation).
What This Page Covers
This page explains general CT terminology that often appears in radiology reports.✔ Neutral definitions
✔ No medical advice
✔ No interpretation of your CT images
✔ No diagnosis or severity statements
✔ For educational use only
Common CT Terms and Their General Meaning
Attenuation / Hyperattenuating / Hypoattenuating
These terms describe how dense something looks on a CT scan.
• Hyperattenuating → appears brighter (often blood, bone, calcification, metal, or contrast)
• Hypoattenuating → appears darker (often fluid, fat, or some soft tissues)The term attenuation simply refers to the density of a structure on CT.
Contrast Enhancement
When IV contrast is given, tissues may “enhance,” meaning they become brighter because they absorb the contrast material.This only describes how a structure reacts to contrast, not what the cause is.
Calcification
Calcification means calcium deposits are present.
• Can be related to age
• Can be a normal finding (e.g., healed areas, old injuries)
• Appears very bright on CTCalcification alone does not indicate severity.
Nodule
A small, rounded spot seen in an organ or tissue.
• In the lungs: a small, round opacity
• In other organs: simply an area that looks different from surrounding tissueThe term “nodule” is descriptive, not a diagnosis.
Lesion
A very general word meaning “something looks different.”This can refer to:
• A spot
• An area of altered density
• A region that looks unlike surrounding tissueThe term does not describe what it is or whether it is serious.
Effusion
Fluid in a body cavity.Common examples:
• Pleural effusion = fluid around the lungs
• Ascites = fluid in the abdomenEffusion simply means fluid, not the cause.
Effusion
Means fluid inside a joint space (commonly the knee, shoulder, ankle).
Fat Stranding
A term describing streaky, hazy areas in fat on CT.This can be caused by:
• Irritation or inflammation
• Recent surgery or injury
• Infection
• Organ irritation nearbyFat stranding is a descriptive finding only.
Mass
A larger area or structure that appears abnormal compared to surrounding tissue.“Mass” does not describe whether it is benign or malignant — only that it has size and shape.
Artifact
An image distortion that can make something look unusual but is not a real finding.Common causes:
• Motion (moving during the scan)
• Metal (implants, dental fillings)
• Technical factorsArtifacts are common and can reduce image clarity.
Why CT Reports Use Technical Language
Radiology reports are written for other doctors.Technical terms:
• Allow precise, consistent descriptions
• Help clinicians understand the appearance and location of findings
• Do not tell patients whether something is normal or abnormal by themselvesA radiologist’s wording is meant to be accurate, but can be difficult to understand without medical training.
When to Discuss Your Results With Your Doctor
Always speak directly with your doctor if you have questions about your CT report.Your doctor can discuss:
• What the findings mean for your health
• Whether follow-up is needed
• How results connect to your symptoms or treatment planCT terminology alone cannot provide diagnosis, severity, or medical advice.
Plain-Language Explanation Service
If you have trouble understanding your CT report wording, you can request a clear, neutral explanation that simply restates:• General meaning of the terms used
• What structures the report is referring to
• Definitions of technical phrases
• The radiologist’s descriptive languageThis helps you feel more informed when discussing the results with your doctor.
Important Disclaimer
This page provides general, educational information about CT terminology only.
It does not:
• Diagnose medical conditions
• Interpret your CT images
• Give medical opinions
• Replace professional medical careAlways discuss your personal report with your healthcare provider.