Initial clinical results with a new needle screen storage phosphor system in chest radiograms

Purpose: To evaluate image quality and anatomical detail depiction in dose-reduced digital plain chest radiograms using a new needle screen storage phosphor (NIP) in comparison to full dose conventional powder screen storage phosphor (PIP) images. Materials and Methods: 24 supine chest radiograms were obtained with PIP at standard dose and compared to follow-up studies of the same patients obtained with NIP with dose reduced to 50% of the PIP dose (all imaging systems: AGFA-Gevaert, Mortsel, Belgium). In both systems identical versions of post-processing software supplied by the manufacturer were used with matched parameters. Six independent readers blinded to both modality and dose evaluated the images for depiction and differentiation of defined anatomical regions (peripheral lung parenchyma, central lung parenchyma, hilum, heart, diaphragm, upper mediastinum, and bone). All NIP images were compared to the corresponding PIP images using a five-point scale (- 2, clearly inferior to + 2, clearly superior). Overall image quality was rated for each PIP and NIP image separately (1, not usable to 5, excellent). Results: PIP and dose reduced NIP images were rated equivalent. Mean image noise impression was only slightly higher on NIP images. Mean image quality for NIP showed no significant differences (p > 0.05, Mann-Whitney U test). Conclusion: With the use of the new needle structured storage phosphors in chest radiography, dose reduction of up to 50% is possible without detracting from image quality or detail depiction. Especially in patients with multiple follow-up studies the overall dose can be decreased significantly.