Value Of Dynamic Three-dimensional Contrast-enhanced Ultrasonography In The Diagnosis Of Hepatic Tumors

Hepatic tumors are commonly encountered disease clinically, and different tumors have different therapy and prognosis. Malignant hepatic tumors such as hepatocellular carcinoma and cholangiocellular carcinoma need therapy including surgery, radiofrequency ablation and transcatheter arterial chemoembolization; while benign hepatic tumors such as hepatic haemangioma, focal nodular hyperplasia usually only need regular follow-up and do less harm to human health, and it’s necessary to remove only when it is large enough. So, it’s especially important to make a differential diagnosis of hepatic tumors.Vascularity of tumor plays a very important role in the diagnosis of hepatic tumors. Both contrast-enhanced CT and contrast-enhanced MRI are the most widespread imaging techniques used to evaluate vascularity of hepatic tumors and thus to make differential diagnosis of them. Contrast-enhanced ultrasonography is an emerging imaging technique which is as useful as the above two in the examination of livers. What’s more, contrast-enhanced CT (or contrast-enhanced MRI) scans only in the special moment for the special phase, while contrast-enhanced ultrasonography scans during the whole contrast-enhanced period, so the latter could find some important information which might be missed by the former.Contrast-enhanced CT (or contrast-enhanced MRI) displays mainly cross plane, sagittal plane and coronal plane of liver, while contrast-enhanced ultrasonography displays the flexible plane. All these images are two-dimensional planes, and the anatomic structures are three-dimensional, when the clinic physicians evaluate the tumor and the relationship between tumor and the adjacent tissue, they have to integrate all the two-dimensional information to obtain the three-dimensional anatomic structure imaging. This is inconvenient and may lead to mistake.Dynamic three-dimensional contrast-enhanced ultrasonography(3D-CEUS) is the up-to-date technique of three-dimensional ultrasound imaging, it’s on the basis of contrast-enhanced ultrasonography. to complete the course of collecting, reconstructing and displaying many three-dimensional images of the region of interest during several seconds, so it can display the dynamic contrast-enhanced perfusion images in the perspective of three-dimension of tissue and structure. In the study, we performed the dynamic3D-CEUS examination on114patients (including118hepatic tumors) to evaluate the clinic clinical value of this new technique.Part I:Imaging of hepatic tumors with dynamic3D-CEUSObjective To investigate the value of dynamic3D-CEUS in the differential diagnosis of different hepatic tumors.Methods Totally,114patients with118focal liver lesions (only the most significant lesion was involved into the study when there were several lesions of one patient;2different tumors at the same scanning plane in3patients; and there was one patient examined both before and after radiofrequency ablation) were examined with conventional ultrasonography, two-dimensional contrast-enhanced ultrasonography(2D-CEUS) and dynamic3D-CEUS by PHILIPS iU22ultrasonography scanning system. Enhancement patterns in arterial phase, different echogenicity in different phases, three-dimensional effect of tumors in different phases, definition of blood vessel and spatial relationships of tumor and vascularity of different hepatic tumors in arterial phase were observed and the value of dynamic3D-CEUS in differential diagnosis of hepatic tumors was also evaluated.Results Enhancement patterns in arterial phase included whole enhancement, ring enhancement, centripetal enhancement, centrifugal enhancement and non-enhancement in our study. There were hyperechoic, isoechoic, hypoechoic and anechoic during different phases. Different hepatic tumors displayed different dynamic3D-CEUS images. The sensitivity, specificity and positive predictive value were92.5%(62/67),90.2%(46/51) and92.5%(62/67) of dynamic3D-CEUS in the diagnosis of hepatocellular carcinoma,92.3%(12/13),97.1%(102/105) and80.0%(12/15) in the diagnosis of metastatic liver tumor,100.0%(9/9),100.0%(9/9) and100.0%(9/9) in the diagnosis of hepatic haemangioma,88.9%(8/9),99.1%(108/109) and88.9%(8/9) in the diagnosis of focal nodular hyperplasia, respectively.Conclusion Dynamic3D-CEUS can display the different enhancement features of hepatic tumors in three-dimensional vision, which is useful in differential diagnosis of focal liver lesions. Part Ⅱ:Comparison of enhancement features of hepatic tumors between dynamic3D-CEUS and2D-CEUSObjective To investigate the enhancement features of hepatic tumors between dynamic3D-CEUS and2D-CEUS.Methods Examination is the same with part Ⅰ. Enhancement patterns in arterial phase, different echogenicity in different phases, sharpness or three-dimensional effect in different phases, definition of blood vessel and spatial relationships of tumor and vascularity of different hepatic tumors in arterial phase on the two imaging modes were compared statistically, the value of two modes in differential diagnosis of hepatic tumors were also evaluated.Results Dynamic3D-CEUS was similar to2D-CEUS with respect to enhancement patterns, sharpness or three-dimensional effect of tumor in different phases (P>0.05). And there was no significant difference between the value of dynamic3D-CEUS and2D-CEUS in differential diagnosis of hepatic tumors:the sensitivity, specificity, positive predictive value and negative predictive value were91.0%,78.1%,91.0%and78.1%for dynamic3D-CEUS, and were92.0%,78.1%,93.0%and80.6%for2D-CEUS, respectively. However, dynamic3D-CEUS was superior to2D-CEUS in the display of definition of blood vessel and spatial relationships of hepatic tumor and vascularity in arterial phase (P<0.05).Conclusion Dynamic3D-CEUS is a useful technique in the differential diagnosis of hepatic tumors as well as2D-CEUS, and dynamic3D-CEUS displays the blood vessel and spatial relationship of hepatic tumors and vascularity in arterial phase more visually and effectively.Part Ⅲ:Evaluation of the vascularity of hepatocellular carcinoma between dynamic3D-CEUS and contrast-enhanced CT (or contrast-enhanced MRI)Objective To evaluate the vascularity of hepatocellular carcinoma between dynamic3D-CEUS and contrast-enhanced CT (or contrast-enhanced MRI).Methods Fifty-five patients with55hepatocellular carcinomas were examined with conventional ultrasonography and dynamic3D-CEUS by using PHILIPS iU22ultrasound system, and the dynamic3D-CEUS images were processed and evaluated. Enhancement levels during arterial phase and portal phase of dynamic3D-CEUS were observed. According to the enhancement levels, tumors’vascularity were divided into four types:hypervascular, isovascular, hypovascular and avascular. All the results were compared with contrast-enhanced CT (or contrast-enhanced MRI).Results Four lesions after local therapy didn’t show any enhancement in both dynamic3D-CEUS and contrast-enhanced CT. The other51lesions showed different enhancement levels:the percents of hyperenhancement in arterial phase of dynamic3D-CEUS and contrast-enhanced CT (or contrast-enhanced MRI) were98.0%(50/51) and92.2%(47/51), respectively; and the percents of hypoenhancement in portal phase were both82.4%(42/51). There was no significant difference between the two methods in displaying the vascularity of hepatocellular carcinoma in arterial and portal phases (both P>0.05).Conclusion Dynamic3D-CEUS displays the vascularity of hepatocellular carcinoma as accurate as contrast-enhanced CT (or contrast-enhanced MRI).