Elastography in Microwave Ablation of Benign Thyroid Nodules: Relationship with Thyroid Function Levels and Contrast Enhanced Ultrasound Imagine

Abstracts Methods: Conventional breast US and SWE were performed in 99 women with 110 palpable breast lesions (52 benign, 58 malignant). All cases were either pathologically confirmed or showed no interval change over 6 months. Diagnostic performance, optimal cutoff value and pathological correlation for each quantitative SWE parameter were calculated by ROC curve and independent t test. Association between SWE color pattern and BI-RADS category were assessed by Chi-squared test. Results: Of the 110 palpable breast masses, 52 masses (47.3%) were benign and 58 masses (52.7%) were malignant. Mean Emax of malignant masses (109.3 6 75.6 kPa) was significantly higher than that of benign (26.2 6 20.9kPa) (p , 0.001). SWE ratio between the lesion and adjacent fat was higher in malignant masses than benign, as follows; 11.3 6 10.6 and 3.4 6 3.1. Optimal cutoff values derived for mean Emax and SWE ratio were respectively, as follows; 45.1kPa and 5.3. SWE color pattern and both BI-RADS category and reference standard were significantly associated (p , 0.001). Also, SWE color pattern and echogenic halo around the lesion on conventional US were significantly associated (p , 0.001). Conclusions: The quantitative SWE features provide good diagnostic performance in palpable mass. In addition, color overlay pattern on SWE can provide diagnostic value, when added to conventional breast US findings, such as echogenic halo. PPT7-005 Diagnostic Value of Acoustic Radiation Force Impulse (ARFI) Elastography for Differentation of Hemangiomas from Malignant Liver Lesions during Conventional Abdominal Ultrasound Giovanni Galati, Antonio De Vincentis, Paolo Gallo, Umberto Vespasiani, Alessandro Guidi, Antonio Picardi Department of Hepatology, University Campus Bio Medico, Italy Objectives: Background and aimSolid focal liver lesions (FLLs) are very common findings during conventional abdominal ultrasound (US). Among benign FLLs, hemangiomas are very frequent. Acoustic Radiation Force Impulse (ARFI) is an ultrasound-based elastography method, able to non-invasively evaluate the stiffness of FLLs. Aim of this study was to assess the diagnostic value of US ARFI, for characterizing hemangiomas Vs malignant FLLs. Methods: Inclusion criteria were presence of hemangiomas or malignant FLLs; definite diagnosis by histological evaluation or $ 1 radiological exam with contrast medium (CT, MRI, CEUS). ARFI quantification was performed with an Acuson S3000 ultrasound system (SiemensÒ, Munich, Germany). Two experienced operators performed five measures per lesion and five measures in the surrounding liver. Results: One-hundred-and-nine FLLs (44 Hemangiomas [HEs], 38 Hepatocellular Carcinomas [HCCs] and 27 metastases [METs]) were examined. HEs showed a significantly lower stiffness compared to malignant FLLs (HEs median value 1.32, IQR 0.97-1.84 m/sec; malignant lesions median value 2.72, IQR 2.00-3.54 m/sec; p,0.001) [Figure 1A]. Conversely, no differences were found for nodule-to-parenchyma ARFI ratios and between HCCs and METs. ARFI values were able to correctly differentiate malignant lesions with a c-statistics of 0.85 (95%CI 0.770.93) and sensitivity of 75.4%/specificity of 84.1% at a cut-off of 2.00 m/sec. Conclusions: This study highlights the possibilities arising from the new technologies available in conventional abdominal US. In particular, our results suggest that ARFI can distinguish between HEs and malignant lesions (HCCs and METs) at a cut-off of 2.00 m/sec.

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PPT7-006 Elastography in Microwave Ablation of Benign Thyroid Nodules: Relationship with Thyroid Function Levels and Contrast Enhanced Ultrasound Imagine Qian Yang,1 Peng Tang,2 Guangbin He,1 Liwen Liu,1 Shuping Ge,3 Xiaodong Zhou1 1 Department of Ultrasound, Xijing Hospital, China, 2Department of Orthopedics and Rehabilitation, China Rehabilitation Research Center, 3Department of Pediatrics, St. Christopher’s Hospital for Children Objectives: Elastography has been proposed to increase the sensitivity of ultrasound and improve the detection of Benign Thyroid Nodules after microwave ablation, and to investigate the applicability of these diagnostic methods for follow-up. Specifically, the correlation between T3, T4, TSH and elastography score, as well as other clinical and contrast enhanced ultrasound (CEUS) imagine features, was analyzed. Methods: Patients with Benign thyroid nodule identified by from March 2016 to May 2017 and undergoing ultrasound, elastography, and thyroid function evaluation were selected before and after ultrasound-guided thermal microwave ablation. QontraXt software to determine the time intensity curve (TIC) of Nodules blood perfusion and microvascular changes. The association between suppressed thyroid stimulating hormone and patient’s age, nodule’s size, ultrasound presentation, CEUS, and elastography scoring was analyzed by Odds Ratio in univariate fashion and multivariate model. Results: 91 subjects with single benign thyroid nodule were enrolled. Median age of 52 years, median size of 2.8 cm. Those nodules classified by ultrasound under- went fine-needle aspiration cytology and malignancy tumor was excluded. Before microwave ablation, elastography detected a median elasticity score of ES 2 6 0.4, and after ablation the median score was ES 3 6 0.7, and stimulating hormone significantly lower than the other (p , 0.001). A model of multivariate logistic regression including nodule’s size, ultrasound characteristics, and elastographic presentation showed that thyroid nodule after ablation elasticity score was significantly associated with suppressed thyroid stimulating hormone (Odds Ratio of 50). Conclusions: Strain elastography detects decreasing tissue elasticity and CEUS TIC provides quantifiable results and is promising as a diagnostic follow-up after microwave ablation associated with reduced/suppressed thyroid stimulating hormone.

PPT7-008 Investigate the Efficacy of Using Quantitative Elastography with Supersonic Shear Imaging in Renal Transplants Yanqing Wang Department of Ultrasonic Medical Science, People’s Hospital of ZhengZhou, China Objectives: Compare the renal cortex in patients with and without rejection reaction after kidney transplantation. Evaluate the accuracy of using quantitative elastography with Supersonic shear imaging to show the rejection reaction after kidney transplantation. Methods: Measure and compare the Young’s modulus of renal cortex in 41 patients, including 36 without rejection and 5 with rejection, after receiving kidney transplantation, by using an ultrafast ultrasound device (AixplorerÒ, SuperSonic Imagine, Aix-enProvence,France).