Characterization of small focal liver lesions using real-time contrast-enhanced sonography: diagnostic performance analysis in 200 patients.
OBJECTIVE
The purpose of this study was to assess the diagnostic performance of real-time contrast-enhanced sonography in characterization of small focal liver lesions (FLLs; < or = 3.0 cm in diameter).


METHODS
Two hundred small FLLs in 200 patients were examined by contrast-enhanced sonography using a contrast-specific mode of contrast pulse sequencing and a sulfur hexafluoride-filled microbubble contrast agent. The sonographic images were reviewed by 2 independent readers. A 5-point confidence level was used to discriminate malignant from benign FLLs, and specific diagnoses were recorded. The diagnostic performances were evaluated by receiver operating characteristic (ROC) analysis, and the interobserver agreement was analyzed by weighted kappa statistics.


RESULTS
After review of contrast-enhanced sonography, ROC analysis revealed significant improvement in differentiating between malignant and benign small FLLs that the areas under the ROC curve were 0.856 at baseline sonography versus 0.954 at contrast-enhanced sonography for reader 1 (P < .001) and 0.857 versus 0.954 for reader 2 (P = .003). The sensitivity, negative predictive value, and accuracy for both readers also improved significantly after contrast agent administration (all P < .001). A better result of specific diagnosis was obtained (38.5% [77/200] at baseline sonography versus 80.5% [161/200] at contrast-enhanced sonography for reader 1 and 34.5% [69/200] versus 80.5% [161/200] for reader 2; both P < .001) after contrast agent administration, and a better interobserver agreement was achieved (kappa = 0.425 at baseline sonography versus 0.716 at contrast-enhanced sonography).


CONCLUSIONS
Real-time contrast-enhanced sonography improves the diagnostic performance in small FLLs compared with baseline sonography.
Xu
Hui-Xiong
HX
Department of Medical Unltrasonics, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Rd 2, Guangzhou 510080, China.
Liu
Guang-Jian
GJ
Lu
Ming-De
MD
Xie
Xiao-Yan
XY
Xu
Zuo-Feng
ZF
Zheng
Yan-Ling
YL
Liang
Jin-Yu
JY
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003287:Contrast Media / Q000008:administration & dosage*; D018618:Echocardiography, Doppler, Color / Q000379:methods; D005260:Female; D006104:Granuloma, Plasma Cell / Q000175:diagnosis; D006391:Hemangioma / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging*; D008107:Liver Diseases / Q000175:diagnosis*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride / Q000008:administration & dosage
D003287:Contrast Media; D013459:Sulfur Hexafluoride