Imaging Tests in Plain Language
Educational orientation
Source-checked: 2026-06-05. This page explains imaging concepts; it does not read scans.
Core Idea
Imaging tests create pictures or signals from inside the body. X-ray, CT, MRI, ultrasound, PET, and nuclear medicine scans answer different questions because they measure different physical properties. Some show anatomy. Some show metabolism or tracer uptake. Some guide procedures.
An imaging report often describes location, size, appearance, comparison with prior studies, and uncertainty. It may suggest possibilities rather than prove a diagnosis.
Essential Vocabulary
- Lesion: abnormal area seen on imaging.
- Contrast: substance used to improve visibility.
- Uptake: tracer signal, often in PET or nuclear scans.
- Interval change: difference from a prior study.
What This Does Not Mean
An image finding is not always a diagnosis. Tissue, follow-up, or clinical correlation may be needed.
Builder/Data Lens
Images need metadata: modality, scanner, protocol, contrast, timing, and annotation source. A model trained across mixed protocols can learn artifacts.
Go Deeper
References
- National Cancer Institute. Tests and Procedures Used to Diagnose Cancer
- National Cancer Institute. NCI Dictionary of Cancer Terms