Sandbox Mode — No Real Patient Data. The platform is operating under the Production Health Data Lock. RadStart Academy learning, reflection and CPD entries must not contain identifiable patient information or real clinical case data. Regulatory confirmations: 0 of 9 complete.

CT Principles
20 min

How CT forms an image

From rotating tube to reconstructed slice.

Video placeholder — lesson recording to be added.

Lesson recording to be uploaded by the Academy administrator.

Written content

A CT image is not a photograph. The tube and detectors rotate around the patient collecting attenuation profiles from hundreds of angles, and a reconstruction algorithm turns those profiles into a cross-sectional map of tissue density. Every choice you make at the console — rotation time, pitch, reconstruction kernel — changes that map.

Understanding this sequence is what separates a radiographer who follows a protocol from one who can reason about it. When an image looks wrong, the explanation almost always lies somewhere in this chain.

Slice reconstruction summary sheet

Downloadable resource placeholder — file to be uploaded by the Academy administrator.

Knowledge check

2 questions. Sign in to record your score.

  1. 1. What does a CT detector array actually measure?

  2. 2. Which value describes tissue density on a CT image?

Next lesson