Dual-energy chest radiography with a flat-panel digital detector: revealing calcified chest abnormalities.
OBJECTIVE
The aim of this study was to assess the value of dual-energy chest radiography obtained using a cesium iodide flat-panel detector in addition to standard posteroanterior chest radiography for the detection of calcified chest abnormalities.


METHODS
The study included 20 patients with a total of 37 calcified chest lesions (16 pulmonary nodules, 17 mediastinal calcifications, and four pleural calcifications) as confirmed on CT. Twenty-eight locations in the chests of the same patients who were free of lesions were used as negative controls. Four radiologists reviewed posteroanterior chest radiographs in a blinded manner alone and in conjunction with dual-energy soft-tissue and bone images. We calculated sensitivity, specificity, the negative predictive value (NPV), and the positive predictive value (PPV) for lesion prediction. The Wilcoxon's and the Brunner and Langer's tests were performed for statistical analysis.


RESULTS
For posteroanterior chest radiography, sensitivity was 36%, the PPV was 64%, and the NPV was 47%. When dual-energy images were added, sensitivity increased significantly to 66% (p < 0.05), the PPV to 76%, and the NPV to 62%. The specificity remained constant at 73%. Brunner and Langer's test revealed a highly significant difference between posteroanterior chest radiography and dual-energy imaging in the detection of calcified chest abnormalities (p < 0.01).


CONCLUSIONS
Dual-energy images added to standard posteroanterior chest radiographs significantly improve the detection of calcified chest lesions.
Fischbach
Frank
F
Department of Radiology, Charité, Campus Virchow-Klinikum, Humboldt-University Medical School, Augustenburgerplatz 1, 13353 Berlin, Germany. frank.fischbach@charite.de
Freund
Torsten
T
Röttgen
Rainer
R
Engert
Ulrike
U
Felix
Roland
R
Ricke
Jens
J
D000368:Aged; D002114:Calcinosis / Q000000981:diagnostic imaging*; D002586:Cesium; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007454:Iodides; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008477:Mediastinal Diseases / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010995:Pleural Diseases / Q000000981:diagnostic imaging*; D015900:Radiography, Dual-Energy Scanned Projection / Q000295:instrumentation*; D013902:Radiography, Thoracic / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007454:Iodides; D002586:Cesium; C040050:cesium iodide