A radiologist reading an abdominal CT sets the display window to a width of centred…
PHYSICS · Multi-part · Fermi University Physics · Biophysics & Medical Physics · Radiation physics and diagnostic imaging · Radiation physics and diagnostic imaging
Life at Thermal Energy, Ch Images from attenuation and from decay
Problem
A radiologist reading an abdominal CT sets the display window to a width of 350HU centred on a level of +40HU, a common setting for soft tissue.
((a)) Find the two Hounsfield values that this window maps to pure black and to pure white.
((b)) A small liver lesion reads +65HU against surrounding liver tissue at +55HU. Both values lie inside the window. Find what fraction of the full black-to-white grey scale separates the two, expressed as a percentage.