Radiology Glossary

This glossary summarizes basic terms that often appear in radiology reports and conversations. Knowing these terms makes it easier to discuss results with your doctor.

Anatomy and finding terms

Lesion: an abnormal area of tissue that is not necessarily dangerous. Nodule: a small, roughly round mass. Mass: an area larger than a nodule. Calcification: calcium deposits that often look very white.

Effusion: fluid accumulation in a body cavity. Consolidation: a lung area filled with fluid or inflammatory cells, often seen in pneumonia. Atelectasis: partial collapse of lung tissue.

Image density terms

Radiopaque: appears white because it absorbs many rays, such as bone. Radiolucent: appears dark because it absorbs few rays, such as air. Hyperdense and hypodense (CT): brighter or darker than surrounding tissue, respectively.

Opacity: an area that looks whiter than expected. Enhancement: increased brightness after contrast, indicating blood flow to tissue.

Technique and contrast terms

Contrast: a substance that highlights organs or vessels. Iodinated contrast is used in CT, while barium is used for the digestive tract. Protocol: the set of exam parameters defined by a facility.

Artifact: a false image caused by metal, motion, or technical factors. Effective dose (mSv): an estimate of radiation risk that combines effects across organs.

Key points

• Lesion: an abnormal area in tissue.
• Contrast: a substance that helps highlight organs or vessels.

Educational information, not a substitute for medical advice.