Radiation dose reduction with application of non-linear adaptive filters for abdominal CT

Figure 1 Transverse abdominal computed tomography images in a 72-year-old woman who underwent radiofrequency ablation for renal cell carcinoma showing a renal cyst (white arrow) in the left kidney at four different tube current- time product levels (200, 150, 100 and 50 mAs). Three lower tube current-time products (150, 100 and 50 mAs) when processed with 2D-non-linear adaptive filters showed lower image noise without affecting image contrast.

Figure 2 Non-linear adaptive filters divides the original image into a number of frequency bands, which are processed separately and ultimately re-combined into a resultant final image. NLAF: Non-linear adaptive filters.