Contrast-enhanced sonography in the diagnosis of small hepatocellular carcinoma < or =2 cm.
OBJECTIVE
To evaluate the usefulness of contrast-enhanced sonography (CEUS) in the diagnosis of small hepatocellular carcinoma (HCC) measuring < or =2 cm in diameter.


METHODS
We identified 104 focal liver lesions measuring < or =2 cm in 104 consecutive patients who were enrolled for baseline sonography (BUS) and CEUS examination (49 HCCs, 55 non-HCCs). A real-time, contrast-specific mode of contrast pulse sequencing and a sulphur hexafluoride-filled microbubble contrast agent were used for CEUS. The diagnostic performances of BUS and CEUS in differentiating focal liver lesions (HCC or non-HCC) were analyzed and compared.


RESULTS
On CEUS, 43 (87.8%) of the 49 HCC lesions were hyperenhanced, 5 (10.2%) were isoenhanced, and 1 (2%) was hypoenhanced during the arterial phase when compared with adjacent liver tissue. Thirty-nine (79.6%) HCCs exhibited washout from the portal phase to the late phase. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy before and after contrast agent administration were 28.6% (14/49) versus 79.6% (39/49) (p < 0.001), 94.5% (52/55) versus 92.7% (51/55) (p > 0.05), 82.4% (14/17) versus 90.7% (39/43) (p > 0.05), 59.8% (52/87) versus 90.7% (39/43) (p < 0.01), and 63.5% (66/104) versus 86.5% (90/104) (p < 0.001), respectively. No significant difference in diagnostic performance of CEUS was found between lesions measuring < or =1.5 cm and those 1.6-2 cm and between lesions located at a depth of < or =6 cm from the skin and those located deeper.


CONCLUSIONS
CEUS significantly improved the diagnostic performance in characterization of small HCCs < or =2 cm compared with BUS.
Xu
Hui-Xiong
HX
Department of Medical Ultrasonics, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, People's Republic of China.
Xie
Xiao-Yan
XY
Lu
Ming-De
MD
Liu
Guang-Jian
GJ
Xu
Zuo-Feng
ZF
Zheng
Yan-Lin
YL
Liang
Jin-Yu
JY
Chen
Li-Da
LD
D000328:Adult; D000368:Aged; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013459:Sulfur Hexafluoride; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
D013459:Sulfur Hexafluoride