The Feasibility Study of Contrast-enhanced Ultrasound Using a 3 Dimension Transducer for Tumor Volume Measurement in Rabbit Hepatic VX2 Carcinoma Comparison with 2 Dimension Ultrasound and 3 Dimension Ultrasound without Contrast: Preliminary Results

Background/Aims: To investigate the feasibility of tumor volume measurement using contrastenhanced ultrasound (US) with 3 dimension transducer (3D CEUS) in rabbit hepatic VX2 carcinoma. MethodsThree different tumor volume measurements, including 2D US using the equation, 4/3(π)(abc), 3D US without contrast, and 3D CEUS were performed in 35 rabbit hepatic VX2 carcinomas. With the tumor volume from computerized tomography (CT) as a reference standard, we compared difference between CT volume and each different US tumor volume. The mean difference and correlation coefficient between each US volume measurement and CT volume were analyzed. ResultsTumor volume measurement using 3D CEUS and 2D US using equation showed no statistical difference compared to CT volume (0.276 cm3, 0.212 cm3, and 0.263 cm3 vs. 0.306 cm3, 0.247 cm3, 0.276 cm3, P>0.05). However, 3D CEUS provided the highest correlation coefficient with CT volume (R=0.835 and 0.720) and the highest intraclass correlation (0.973 and 0.993). 3D CEUS provided a smaller mean difference with CT volume (0.016 cm3 and 0.033 cm3) than 2D US, showing 3D CEUS’s accurate measurement of tumor volume. ConclusionsDue to its highly accurate, reliable, and reproducible measurements of tumor volume, 3D CEUS may be useful for predicting the therapeutic response evaluation after treatment.