Subjective evaluation of a novel method of dose reduction by optical re-exposure of conventional radiographs - a multi-observer region of interest evaluation in an animal model.
A procedure previously been described that has an effect on the image quality and radiation dose of conventional radiographs already at the time of acquisition [Paech A, Schulz AP, Hahlbrauck B, Kiene J, Wenzl ME, Jürgens C. Physical evaluation of a new technique for X-ray dose reduction: measurement of signal-to-noise ratio and modulation transfer function in an animal model. Physica Medica 23 (2007):33-40]. This development is using X-ray sensitization by optical re-exposure. Aim of this study was to establish if the results of optical re-exposure measured with SNR and MTF also meant that the subjective quality of 50% dose-reduced and re-exposed radiographs of bony structures was equal or better than conventional full dose radiographs of the same area. Freshly slaughtered anterior shoulders of lambs served as the animal model. A comminuted fracture in the middle of the shaft was artificially produced. After taking a normal exposed reference image, dose-reduced, five underexposed images were prepared. These underexposed X-rays were then optically re-exposed for a defined period of time before development. The subjective changes in the image quality (information loss or gain) of the images were compared to the reference image and evaluated by 16 physicians with large experience in diagnosis of orthopedic radiographs. The evaluation of the observers scoring showed a significant decrease in the subjective image quality regarding the detail recognition in all images apart from the images re-exposed for 60s. In conclusion, there is a possibility of reducing the collective radiation dose whilst keeping a high degree of diagnostic reliability. Film sensitization provides a technically simple and inexpensive procedure, which can be easily integrated into common film development processes and could considerably reduce patient radiation exposure as well as improve image quality and thus detail recognition.
Paech
A
A
University Hospital Schleswig Holstein, Campus Lübeck, Department of Orthopaedics and Trauma, Ratzeburger Allee 160, 23538 Lübeck, Germany. a.paech@apschulz.de
Schulz
A P
AP
Seide
K
K
Faschingbauer
M
M
Jürgens
Ch
Ch
D000465:Algorithms; D000818:Animals; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D066298:In Vitro Techniques; D023421:Models, Animal; D015588:Observer Variation; D055095:Optics and Photonics; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012756:Sheep; D012782:Shoulder / Q000000981:diagnostic imaging*