Sonography under daylight conditions

Purpose: Gray scale image assessment in clinical ultrasound requires workin g in dim light or a dark room. Daylight conditions offer the advantage of s horter visual reaction time and enhanced visual perception. Look-up table m anipulations could improve image brightness. Materials and Methods: We inve stigated the possibility of brightness and contrast enhancement of coloured adaptive linear look-up tables (CALUTs) and their artifact resistance. The refore under real-time conditions red/brown, green and blue CALUT's were ca lculated using the gray scale distribution (mean and standard deviation) of the actual image. The changes in contrast of several structural features ( echo-poor and echogenic lesions, artifacts) were assessed by clinical inves tigators (n = 7). Results: The CALUT's produced, independent of the origina l, images with constant brightness and contrast. Even under daylight condit ions no artifacts appeared. Under scotopic conditions the red/brown CALUT's showed the best results compared to the unchanged image and the gray, gree n, and blue CALUT's. Hyper and hypoechoic differences with small contrast t o the surrounding tissue are enhanced and can be detected more easily. Conc lusion: Daylight sonography allows examination even in non-darkened rooms w ithout loss of information. Eye adaptation to changing light conditions is no longer necessary; the offered image information is more suitable for the eye.