Perception‑based, Nonuniform Color Mapping for CT Reading

BACKGROUND: With modern CT technology offering faster acquisition, lower radiation exposure, higher resolution, and advanced detector designs, routine image interpretation still relies largely on gray‑scale windowing, which by design requires frequent manual adjustment. Existing color mappings rely on uniform mathematical gradients and offer no clear advantage over gray‑scale display for tissue or structure perception. OBJECTIVE: To develop and evaluate a software framework supporting interactive exploration of perception‑based color mapping. MATERIALS AND METHODS: A custom research DICOM viewer enabling interactive nonuniform color display was developed. Verification included a contrast‑agent dilution series compared with a clinical viewer and liver phantom CT scans with predefined lesions acquired at varying dose levels and reconstruction settings. Differentiation of tissues and structures in the liver phantom was examined by visual rating after application of different color mappings. RESULTS: Quantitative verification using a contrast-agent dilution series confirmed correct mapping of CT values to color. In a phantom-based reader evaluation using liver phantom CT scans, nonuniform color mapping produced stable visual representations and was significantly preferred in subjective visual analysis. CONCLUSIONS: Unlike uniform color mappings, the proposed approach uses nonuniform color ranges to better match human perception. In CT, this may facilitate visual separation of tissues and structures and was preferred in phantom‑based visual assessment compared with standard uniform display methods.