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

Table 1 Lesion detection and subjective image quality scores for abdominal computed tomography examinations for non-linear adaptive filters processed and unprocessed image groups at four different radiation dose levels

	Baseline (200 mAs)	Unpro (150 mAs)	Pro (150 mAs)	Unpro (100 mAs)	Pro (100 mAs)	Unpro (50 mAs)	Pro (50 mAs)
No. of lesions	31	31	31	31	31	31	31
Lesion size (< 1 cm)	28	28	28	28	28	28	28
Lesion conspicuity	1	1	1	1	1	1	1
Image noise	2	3	2	4	2	5	4
Visibility of small structures	3	3	3	4	3	4	4
Image contrast	3	3	3	3	3	3	3
Diagnostic confidence	1	1	1	2	1	4	3

Image noise was lowered and visibility of small structures was enhanced with non-linear adaptive filters processing. Since discrete values cannot be averaged, the table presents the lowest or similar modal scores for lesion conspicuity, image noise, contrast and diagnostic confidence given by radiologists. Unpro: Unprocessed; Pro: Processed.