Evaluation of quantitative contrast harmonic imaging to assess malignancy of liver tumors: A prospective controlled two-center study

Abstract

AIM:To e s t a b l i s h t h e e x t e n t t o w h i c h c o n t ra s t enhancement with SonoVue in combination with quantitative evaluation of contrast-medium dynamics facilitates the detection of hepatic tumors. METHODS:One hundred patients with histologically confirmed malignant or benign hepatic tumor (maximum size 5 cm) were analyzed. Contrast-enhanced ultrasound (bolus injection 2.5 mL SonoVue) was carried out with intermittent breath-holding technique using a multifrequency transducer (2.5-4 MHz). Native vascularization was analyzed with power Doppler. The contrast-enhanced dynamic ultrasound investigation was carried out with contrast harmonic imaging in true detection mode during the arterial, portal venous and late phases. Mechanical index was set at 0.15. Perfusion analysis was performed by post-processing of the raw data [time intensity curve (TIC) analysis]. The cutoff of the gray value differences between tumor and normal liver tissue was established using Receiver Operating Characteristic (ROC) analysis 64-line multislice computed tomography served as reference method in all cases. Magnetic resonance tomography was used additionally in 19 cases. RESULTS:One hundred patients with 59 malignant (43 colon, 5 breast, 2 endocrine metastases, 7 hepatocellular carcinomas and 2 kidney cancers) and 41 benign (15 hemangiomas, 7 focal nodular hyperplasias, 5 complicated cysts, 2 abscesses and 12 circumscribed fatty changes) tumors were included. The late venous phase proved to be the most sensitive for classification of the tumor type. Fifty-eight of the 59 malignant tumors were classified as true positive, and one as false negative. This resulted in a sensitivity of 98.3%. Of the 41 benign tumors, 37 were classified as true negative and 4 as false negative, which corresponds to a specificity of 90.2%. Altogether, 95.0% of the diagnoses were classified as correct on the basis of the histological classification. No investigator-dependency (P = 0.23) was noted. CONCLUSION:The results show the possibility of accurate prediction of malignancy of hepatic tumors with a positive prognostic value of 93.5% using advanced contrast-enhanced ultrasound. Contrast enhancement with SonoVue in combination with quantitative evaluation of contrast-medium dynamics is a valuable tool to discriminate hepatic tumors.

Dynamic Contrast‐Enhanced Ultrasound for Quantification of Tissue Perfusion

“…Jung et al 74 investigated 100 patients with histologically confirmed liver tumors (59% malignant). Time-intensity curve analysis after dynamic contrast-enhanced US imaging with SonoVue resulted in sensitivity of 98% and specificity of 90% for diagnosis of malignancy by analyzing the behavior of the lesions in the late phase.…”

“…In animals, it has been demonstrated that tumor characterization and differentiation of benign from malignant tumors are possible by replenishment kinetics. 25,68 Also, in human studies, differentiation between benign and malignant tumors in parenchymatous organs (liver tumors, 35,52,54,74 pancreatic masses, 44,53 lymph nodes ,51,59 breast tumors, 33,34,37,60 prostate nodules, 45,55,58,61,63 adrenal masses, 40 urinary bladder masses, 36 adnexal masses, 50,56 glioblastomas, 75 soft tissue tumors, 76 and thyroid nodules 32 ) could be achieved with dynamic contrastenhanced US and time-intensity curve analysis.…”

Diagnostic accuracy of contrast‐enhanced ultrasound in differentiating benign and malignant focal liver lesions: A retrospective study

“…1 Several authors propose this late phase enhancement to differentiate benign from malignant lesions. 5,6,8,10,[14][15][16][17] The evaluation of early phase enhancement, however, is particularly important for improved specificity especially in a study population which comprised a majority of hypervascular lesions.…”

“…For patients with multiple lesions, only up to three lesions can be distinctly targeted and studied throughout all vascular phases of CEUS because of limited arterial phase time window as a result of rapid contrast uptake and washout of most hypervascular lesions. 8 The detection of additional lesions, especially those that exhibit predominantly arterial enhancement such as HCC, represents another intrinsic limitation of CEUS.…”

“…We use a second generation microbubble contrast agent, SonoVue® (Bracco, Milan, Italy) which allows continuous real-time imaging of FLLs at low mechanical index (MI < 1.5) without bubble destruction as compared with first-generation microbubble contrast agents. 8,9 This has been shown to significantly improve the diagnostic performance over baseline US as it provides important information about the morphologic appearance of the tumour vasculature as well as the dynamic pattern of enhancement and washout that is crucial for lesion characterisation. 6,9 Unlike CT or MRI contrast media which diffuse into the extravascular space in the equilibrium phase, SonoVue® is a true blood pool agent and does not leak into the interstitial space and therefore permits a more accurate depiction of tumour vascularity, especially when coupled with real-time continuous imaging.…”