The authors evaluate a new flat-panel x-ray detector (FD) with respect to foreign body detection and reduction of radiation dose compared with screen-film radiography.
Flat-panel x-ray detector is based on amorphous silicon technology and uses a 1 k x 1 k photo-detector matrix with a pixel size of 143 x 143 µm and 12-bit digital output. A thallium-doted cesium iodide scintillation layer converts x-rays into light. An ex vivo experimental model was used to determine the detectability of foreign bodies. Foreign bodies with varying sizes were examined: glass with and without addition of lead, bone, aluminium, iron, copper, gravel fragments, and graphite. Four hundred observation fields were examined using conventional radiography(speed, 400; system dose: 2.5 µGy) as well as FD with a simulated speed of 400, 800, 1200, and 1600, corresponding to a detector dose of 2.5 µGy, 1.25 µGy, 0.87 µGy, and 0.625µGy, respectively. Four independent radiologists performed receiver operating characteristic analysis of 8000 observations.
Flat-panel x-ray detector with a simulated speed of 400 was significantly superior (P = 0.012) to screen-film radiography (speed, 400). At a simulated speed of 800 and 1200 FD yielded results equivalent to screen-film radiography. Flat-panel x-ray detector was significantly inferior to screen-film radiography at a simulated speed of 1600 (P = 0.012).
Flat-panel x-ray detector technology allows significant reduction in radiation dose compared with screen-film radiography without loss of diagnostic accuracy.
Reprint requests: Markus Völk, MD, Department of Radiology, University Hospital of Regensburg, 93042 Regensburg, Germany; firstname.lastname@example.org.
Received February 5, 1997, and accepted for publication, after revision, March 6, 1997.
From the *Department of Radiology, University Hospital of Regensburg, Regensburg, Germany, and †Siemens AG, Medical Engineering, Erlangen, Germany.
Val M. Runge, MD Lexington, Kentucky
David J. Allison, BSc, MD, MRCP, FRCR;London, United Kingdom
William G. Bradley, Jr., MD, PhD, FACR;Long Beach, California
Claus D. Claussen, MD;Tubingen, Germany
Rosalind B. Dietrich, MB, ChB;Orange, California
Prof. Robert F. Dondelinger;Liege, Belgium
William C. Eckelman, PhD;Bethesda, Maryland
Roland Felix, MD;Berlin, Germany
Paul Finn, MD;Iselin, New Jersey
John C. Gore, PhD;New Haven, Connecticut
Nicholas C. Gourtsoyiannis, MD;Crete, Greece
Herwig Imhof, MD;Vienna, Austria
Gabriel P. Krestin, MD;Zurich, Switzerland
A. C. Lamont, FRCR;Queensland, Australia
Robert B. Lufkin, MD;Los Angeles, California
Claude Manelfe, MD;Toulouse, France
Robert N. Muller, PhD;Mons, Belgium
Lawrence R. Muroff, MD, FACR;Tampa, Florida
Kevin L. Nelson, MD;Omaha, Nebraska
Roberto Passariello, MD;Rome, Italy
Roderic I. Pettigrew, PhD, MD;Atlanta, Georgia
Jeffrey S. Ross, MD;Cleveland, Ohio
Plinio Rossi, MD, FACR;Rome, Italy
Francis W. Smith, MD;Foresterhill, Scotland
Ulrich Speck, MD;Berlin, Germany
David D. Stark, MD;Omaha, Nebraska
H. William Strauss, MD;Stanford, California
Julien L. Struyven, MD;Brussels, Belgium
Gordon K. Sze, MD;New Haven, Connecticut
Michael F. Tweedle, PhD;Princeton, New Jersey
Ad E. Van Voorthuisen, MD;Oeglsgeest, Netherlands
Michael L. Wood, PhD;Toronto, Ontario
Brian S. Worthington, MD;Nottingham, England