Michael Gruber MD, Presenter: Nothing to Disclose

Michael Weber PhD, Abstract Co-Author: Nothing to Disclose

Peter Homolka PhD, Abstract Co-Author: Nothing to Disclose

Stephan Gentzsch MD, Abstract Co-Author: Nothing to Disclose

Julia Fruhwald-Pallamar, Abstract Co-Author: Nothing to Disclose

Martin Uffmann MD, Abstract Co-Author: Nothing to Disclose

A newly developed computed radiography detector which uses a storage phosphor plate made up of needle-shaped crystals provides improved dose efficiency. The aim of our study was to compare image quality of standard-dose computed radiography and dose reduced needle-technology CR for knee imaging in a clinical setting.

We compared standard computed radiography using powder image plates (PIP, Agfa, ADC Compact Plus) to images obtained with the new needle image plates (NIP, Agfa, DX-S). In 30 consecutive patients with knee pain anterio-posterior knee radiographs were aquired with both systems at standard dose. In addition NIP images were obtained with 75% and 50% of standard dose (corresponding entrance skin doses: 300μGy, 235μGy and 154μGy, respectively). Images were evaluated in a blinded side-by-side comparison. Six radiologists determined the presence of an appreciable difference in image quality at 5 different anatomic landmarks in regions with high and low differences of attenuation. They also assessed the delineation of selected abnormalities and ranked them using a ten-point scale. The rating scores were tested for statistical differences using analysis of variance with repeated measures.

There was a significant difference in favor of the NIP system at the same dose level (p<0.05). Also the NIP images obtained with 75% dose were ranked significantly better compared to PIP concerning both the anatomic landmarks and the depiction of abnormalites. The readers ranked half dose NIP images equivalent regarding abnormalities and anatomic landmarks in areas with high differences of attenuation, although in areas with low attenuation differences the image quality was regarded inferior compared to the standard technique.

The NIP technology allows for a dose reduction of about 25% compared to PIP while providing higher image quality. Even at half dose level there is no relevant loss of image quality regarding the delineation of abnormalites in anterio-posterior knee images.

The higher dose efficiency of the needle detector CR technology compared to conventional CR can be utilized either for dose reduction or for improved image quality.

Gruber, M, Weber, M, Homolka, P, Gentzsch, S, Fruhwald-Pallamar, J, Uffmann, M, Needle Image Plates versus Conventional CR: Feasibility of Dose Reduction in Musculoskeletal Radiography.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6014571.html