Value Of Parametric Imaging Of Contrast-Enhanced Ultrasound In Diagnosing Focal Liver Lesions

Objective:To investigate the application of parametric imaging of contrast-enhanced ultrasound (CEUS) in evaluating focal liver lesions (FLLS).Methods:Eighty-eight patients with FLLS undergone CEUS were divided into malignant (n=48) and benign (n=40) groups. SonoLiver CAP software was used to quantitatively analyze the CEUS parameters and reconstruct dynamic vascular patterns (DVP) parametric images in order to compare parameters and DVP have any difference between the benign and malignant groups.Results:The quantitative parameters included maximum intensity (IMAX), rise time (RT), time to peak (TTP), mean transit time (MTT), perfusion index (PI), rising slope (RS), descending slope (DS), falling time of peak intensity (2MTT-TTP). We defined RT, TTP, PI and RS as perfusion parameters while MTT, DS and2MTT-TTP as fading parameters.There was no difference in IMAX between the benign and malignant groups (P=0.121), but there was significant difference in both perfusion parameters and fading parameters between the two groups (P <0.05). In benign group, there was significant difference in IMAX and perfusion parameters except the RT as compared with the surrounding liver parenchyma(P<0.05), but there was no significant difference in RT and fading parameters when compared with the surrounding liver parenchyma(P>0.05).In malignant group, there was significant difference in both perfusion parameters and fading parameters when compared with the surrounding liver parenchyma(P<0.05). In DVP curve, the percentage of washout, non-washout and cystic type were10%(4/40),72.5%(29/40) and17.5%(7/40) in benign group; and87.5%(42/48),10.4%(5/48) and2.1%(1/48) in malignant group, respectively; The difference was statistically significant(P<0.01). In DVP parametric image, the percentage of washout, non-washout and cystic type were10%(4/40),72.5%(29/40) and17.5%(7/40) in benign group; and89.6%(43/48),8.3%(4/48) and2.1%(1/48) in malignant group, respectively; The difference was statistically significant(P<0.01).Conclusions:Parametric imaging of CEUS can clearly and intuitively display the dynamic changes of the enhancement and expurgation of the lesions and surrounding liver parenchyma.