Quantitative Analysis Of Renal Tumors With Contrast-enhanced Ultrasonography

Renal tumors are the common tumors of the urinary system. Most of them are malignant. Many cases are discovered incidentally as this kind of tumors usually has no clinical symptoms. Now ultrasound has been used as the initial screening evaluation for suspected renal diseases. The contrast-enhanced ultrasound(CEUS), as one of most advanced technology in this field, enables the evaluation of the macrovascularization and microvascularization of the tumor. It improves the detection rate of small and deep located lesions and is also useful to discriminate cystic renal lesions. Now it is widely applied in clinical practices.However, both conventional ultrasound and CEUS are subjective modality and much depend upon the experience and a trained eye. Quantitative anylysis based on the soft ware has been studied with the aim of obtaining a sonologist-independent assessment. This approach quantifies the uptake of contrast by a tumor and its washout and may offer more objective and substantial information. The parametric images of the relative dynamic vascular patterns are generated by the software with calculation of the differences between the lesions and the adjacent renal parenchyma. It reflects the different vascular signatures of renal lesions in comparison to neighbouring parenchyma. Quantitative parameters and parametric imaging assess the inflow and outflow of the tumor and offer more objective and comprehensive information. The purpose of this study was to study the features of renal tumors in quantitative analysis and to investigate the value of CEUS with quantitative parameters in the diagnosis and differential diagnosis of renal tumors.Part one Quantitative contrast-enhanced ultrasonography of the renal tumors with different regions of interestObjective To investigate the discrepancy of software-based quantification of contrast-enhanced ultrasound with different depths, sizes and shapes of region of interest.Methods Thirty suspected renal lesions underwent contrast-enhanced ultrasound. Videos were recorded and analysed. Five parameters were calculated, including:the maximum intensity(IMAX), rise time(RT), time to peak(TTP), mean transit time(mTT) and area under the curve(AUC). The influences of depth, size and shape of the region of interest were analysed. Results There were statistical differences in parameters IMAX and AUC in different depths. The variations were41%and54%respectively. No statistical differences were observed in all of the parameters in different sizes and shapes.Conclusions It is important to compare regions of interest (the region of analysis and the region of reference) in the same depth. Size and shape of the region of the interest don’t influence the results.Part two Quantitative analysis of contrast-enhanced ultrasound in renal tumors:a preliminary studyObjective To investigate characteristics of CEUS quantitative parameters in renal lesions and the clinical value.Methods One hundred and thirty-nine cases with renal lesions confirmed by surgery and pathology underwent contrast-enhanced ultrasound preoperatively and quantitative analysis retrospectively. The Sonoliver software was applied in the analysis of CEUS imaging and in the reconstruction of quantitative parameters.Results There are statistical differences between benign tumors and adjacent renal cortex in all of the five parameters.Significant differences are observed in parameters IMAX, AUC, RT and TTP(P<0.01). There are statistical differences in parameters IMAX、AUC and mTT between the malignant tumors and adjacent renal cortex. Significant differences are observed in parameters IMAX and AUC(P<0.01). Comparing the malignant tumors with benign ones, there are statistical differences in parameters IMAX, AUC, RT and mTT, and significant differences are observed in parameters IMAX, AUC(P<0.01).Conclusions Contrast-enhanced ultrasound with a quantitative parametric analysis offers more information of renal tumors.Part three Parametric imaging for characterizing clear cell renal cell carcinoma in contrast-enhanced ultrasoundObjective To investigate the features of quantitative analysis and parametric imaging of contrast-enhanced ultrasound (CEUS) in renal clear cell carcinoma(ccRCC).Methods Ninety-seven ccRCC confirmed by pathology underwent conventional altrasound and CEUS. Sonoliver software was used to acquire quantitative parameters and to reconstruct dynamic vascular pattern(DVP) and DVP parametric images. The DVP curves are divided into4types, type I (Unipolar+), type II (Bipolar+/-), type III (Bipolar-/+), type IV (Unipolar-), while the DVP parametric images are divided into four types too, with type Ⅰ,Ⅱ,Ⅲ,Ⅳ respectively. Results There are statistical differences in parameters IMAX, AUC and mTT (P<0.05). There are no statistical differences in parameters RT, TTP.The percentage of ccRCC were58.8%(57/97) for type I,11.3%(11/97) for type Ⅱ,10.3%(10/97) for type Ⅲ,19.6%(19/97) for type IV in DVP curves, and58.8%(57/97),11.3%(11/97),8.2%(8/97),21.7%(21/97) for each type in DVP parametric images.Conclusions Quantitative analysis and parametric imaging can reflect different features of the ccRCC and offer more information to diagnose the tumors.