| Original | Jpn J Radiol Technol 2000 ; |
| Quantitative Evaluation of Changes in Pleural Effusion Using Digital Images of the Chest |
SHIGEAKI NISHIIKE, ICHIRO FUJIMURA, KENJI SAGARA, KEIJI SAKASHITA |
Department of Radiology, Osaka Prefectural Senshu Critical Care Medical Center |
| Received Nov. 2, 1999; Revision accepted Feb. 7, 2000; Code No. 522 |
| Summary |
| EDR is a function of FCR that automatically determines the optimal density of images. This function makes it difficult to evaluate changes in pleural effusion on sequential chest CR. We developed a method to quantify the amount of pleural effusion using the digital value and S value of chest CR. We evaluated the efficacy of the method to quantify the amount of pleural effusion using these values of chest CR in clinical settings. The study period was from December 1996 to January 1999. Study 1: Chest CR was carried out before and after pleural cavity drainage in 70 cases. The volume calculated with the method using the digital value and S value of CR [x(ml)] was compared with the drained volume [y1] on both sides. Study 2: Change in pleural effusion was estimated with a method using CT(y2)and with the method using the digital value and S value of CR(x). The relationship of these two data was investigated. Study 1: The regression equations between x and y1 were y1=1.05x+21.1(r2=0.89)on the right side and y1=0.95x+69.7(r2=0.68)on the left side. Study 2: The regression equations between x and y2 were y2=0.75x-1.88(r2=0.70)on the right side and y2=0.87x-1.27(r2=0.65)on the left side. The method using the digital value and S value of CR was effective for quantifying changes in pleural effusion. |
| Key words: | Computer-aided diagnosis(CAD), Computed radiography(CR), Imaging plate(IP), Exposure data recognition(EDR), Pleural effusion |
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