window / level
Display parameters that map CT Hounsfield Unit values to screen brightness. "Level" centers the display range; "window" sets the range width. Standard clinical presets:
- Brain: ~80 W / 40 L
- Soft tissue: ~400 W / 40 L
- Lung: ~1500 W / −500 L
- Bone: ~2000 W / 600 L
- Mediastinum: ~350 W / 40 L
Why it matters to buyers: Radiologists toggle between presets during reading. PACS stores presets per protocol; reading-station ergonomics depend on it.
Why it matters to engineers: Calibrated on DICOM-compliant grayscale monitors. Window presets depend on HU calibration being correct — bad HU calibration produces systematically biased displayed values regardless of window settings.