Optimized visualization of contrast medium dependent differences in CT/MRIscans by RGB transformation

Objective: In order to be able to assess the contrast medium enhancement of vessels and regions with disturbed blood-brain barrier, the neurosurgeon m ust mentally perform a subtraction of the corresponding native and contrast -enhanced scans of the CT or MRI. The principle disadvantages of this compa rison are the amount of time required and the potential errors which may re sult from false interpretation. Methods: The process presented here combine s corresponding scans without and with contrast medium off line on a PC. In this process each couple of the black and white scans is assigned to the c olour channels of the RGB system (red, green, blue) and transformed to one colour picture of the RGB colour space (additive colour mixture). Results: We demonstrate that contrast medium-dependent changes can be represented in a colour contrast of complementary colours in one single picture. Addition ally, the unchanged structures remain in the black and white contrast as th ey were before. Conclusion: Thanks to the optimized visualization of contra st medium dependent differences there are besides saving in time further ad vantages such as the reduced amount of pictures and an objective representa tion.