Cross-polarised photography
Definition
A photographic technique using polarising filters on both the light source and the camera lens to eliminate surface glare and reveal subsurface bruising, particularly useful in patients with darker skin tones.
Related terms
- Bilirubin
- A yellow-orange breakdown product of biliverdin, seen as the yellow-brown phase of a resolving bruise. Its appearance indicates advancing haemoglobin degradation.
- Biliverdin
- A green breakdown product of haemoglobin, appearing as the blue-green phase of bruise colour change. Biliverdin is then converted to bilirubin.
- Haemoglobin
- The iron-containing protein in red blood cells that carries oxygen. Its peroxidase-like activity is the basis of most presumptive blood tests; its...
- Oxyhaemoglobin
- The form of haemoglobin in freshly shed arterial blood, where iron in the haem group is in the ferrous (Fe²⁺) state and...
- Tissue laxity
- The looseness of subcutaneous tissue. High laxity (eyelids, scrotum, elderly skin) allows blood to spread widely from a relatively small vessel injury,...
Explained in
- Ageing of Bruises: Methods and LimitationsA photographic technique using polarising filters on both the light source and the camera lens to eliminate surface glare and reveal subsurface bruising, parti...