Hai-Yun Yang

Comparison of ultrasound elastography, mammography and sonography in the diagnosis of solid breast lesions

The purpose of this study was to evaluate the value of ultrasound elastography (UE) in differentiating benign versus malignant lesions in the breast and compare it with conventional sonography and mammography.

Ultrasonic Elastography in Breast Cancer Diagnosis: Strain Ratio vs 5-point Scale

RATIONALE AND OBJECTIVES The aim of this study was to develop a more reliable ultrasonic elastographic diagnostic method than a five-point scoring system by analyzing the difference in stiffness between benign and malignant breast lesions. MATERIALS AND METHODS From January 2008 to April 2009, 559 solid lesions (415 benign, 144 malignant) in 437 consecutive patients (age range, 12-77 years) were examined using ultrasound elastography (UE). Final diagnosis was made on the basis of histopathologic findings. The strain ratios of the lesions were calculated. The area under the curve and cutoff point, both of which were obtained using receiver-operating characteristic curve analysis, were used to assess diagnostic performance. Diagnostic performance was further compared to that generated using a five-point scoring system with the z test. The sensitivity, specificity, and accuracy of these two evaluation systems were compared using McNemars test. RESULTS The strain ratios of benign lesions (mean, 1.83 ± 1.22) and malignant lesions (mean, 8.38 ± 7.65) were significantly different (P < .00001). When a cutoff point of 3.05 was introduced, UE had 92.4% sensitivity, 91.1% specificity, and 91.4% accuracy. The area under the curve for strain ratio-based elastographic analysis was 0.944, and the area under the curve for the five-point scoring system was 0.885. The diagnostic performance of strain ratio-based elastographic analysis was better than that of the five-point scoring system with UE (P < .05). CONCLUSIONS Strain ratio-based elastographic analysis can provide a new, more reliable diagnostic tool in comparison to a five-point scoring system for UE.

Semi-quantitating Stiffness of Breast Solid Lesions in Ultrasonic Elastography

RATIONALE AND OBJECTIVES To explore whether strain ratio measurement could semi-quantitatively evaluate the stiffness of breast lesions. MATERIALS AND METHODS From January 2008 to May 2008, 148 patients with 254 solid lesions (183 benign, 71 malignant) in the breast were included in the study. Ultrasound sonography found the lesions and ultrasonic elastography obtained the strain images. By using the strain ratio measurement method together with the ultrasound machine, the strain index of the lesion was calculated. Different depths of breast tissue were selected as the reference. The strain indexes of malignant and benign solid lesions were calculated with the same level of breast tissue as the reference. RESULTS The strain indexes of breast lesions were different compared to the same depth of breast tissue and the superior level of fat tissue (P = 0.000). The strain indexes of breast lesions were different compared to different depths of breast glandular tissues (P = 0.003). At the same level of the breast lesions, 212 lesions were glandular tissue, 11 were fat tissue, and 40 were both. In the lesion plane, six lesions had almost no glandular tissue and 20 had almost no superior fat tissue. Compared to the same depth of breast tissue, the strain indexes of benign lesions (range, 0.62-11.07) and malignant lesions (range, 3.12-39.28) were different (P = 0.000). CONCLUSION Using the strain ratio measurement, stiffness of breast lesions could be semi-quantitated with the same depth of breast tissue as the reference. This method may provide another diagnostic method in addition to the 5-point scoring system used with ultrasonic elastography in the future.

Antitumoural hydroxyapatite nanoparticles-mediated hepatoma-targeted trans-arterial embolization gene therapy: in vitro and in vivo studies.

Absence of curative treatment creates urgent need for new strategies for unresectable hepatoma. Based on former discoveries of good liver cell compatibility, safety and tumour‐specific inhibition of hydroxyapatite nanoparticles (nHAP), this work tries to make nHAP serve as gene vector in the hepatoma‐targeted trans‐arterial embolization (TAE) gene therapy to elevate and synergize the therapeutic efficacy of TAE and target gene therapy.

Breast Contrast-Enhanced Ultrasound: Is a Scoring System Feasible? ----A Preliminary Study in China

Objectives Although many studies about breast contrast-enhanced ultrasound had been conducted, clear diagnostic criteria for evaluating enhancement patterns are still lacking. This study aims to identify significant indicators for breast contrast-enhanced ultrasound and to establish an initial scoring system. Materials and Methods Totally 839 patients were included in the study. This study was divided into two parts. 364 patients were included in part 1 while 475 in part 2. Conventional ultrasound and contrast-enhanced ultrasound were used to examine each lesion. Only the cases in part 2 were also examined by elastography. In part 1, Logistic regression analysis was performed to predict significant variables. A 5-point scoring system was developed based on the results. In part 2, the scoring system was used to evaluate all the breast lesions. To evaluate the diagnostic efficacy of the new scoring system, it was compared with the system established for elastography and conventional ultrasound (BI-RADS). Results Three independent variables, namely, lesion scope, margin, and shape were selected in the final step of the logistic regression analysis in part 1. In part 2, the area under the ROC (receiver operating characteristic) curve for the contrast-enhanced scoring system was 0.912. The difference in the diagnostic capabilities of the contrast-enhanced scoring system and elastography was not statistically significant (P = 0.17). The difference in the diagnostic capabilities of the contrast-enhanced scoring system and BI-RADS was statistically significant (P<0.001). Conclusions The contrast-enhanced patterns of benign and malignant breast tumors are different. The application of a 5-point scoring system for contrast-enhanced ultrasound is clinically promising.

Hydroxyapatite nanoparticles modified by branched polyethylenimine are effective non-viral vectors for siRNA transfection of hepatoma cells in vitro

Small interfering RNA (siRNA) technology is a powerful tool in biomedical research and holds great potential for RNA interference-based therapies for HIV, hepatitis and cancer. However, the absence of a safe and efficient method for the delivery of siRNA has become a bottleneck for their development. Nanocrystallized hydroxyapatite (nHAP) appears to be an optimal candidate non-viral gene vector for several reasons, including its good biocompatibility and ease of production, however, nHAP microemulsions cannot remain monodispersed for long periods of time. Due to their high surface energy, nHAP particles gradually aggregate into large ones that are difficult for the cell to take up. To overcome this we modified nHAP with polyethylenimine (PEI) to generate a compound (MnHAP) with a tight size-distribution of <200 nm. The positive surface potential of MnHAP inhibited particle aggregation and thus made it easier to conjugate more siRNA. The transfection efficiency of MnHAP/fluorescent FAM-labeled siRNA complex was tested using flow cytometry, and the transfected cells were observed using fluorescence microscopy. The cytotoxicity of MnHAP/siRNA complexes to the human liver cancer cell line BEL-7402 was assessed in vitro by a formazan dye assay. Our results show that the in vitro transfection efficiency of MnHAP/siRNA was equivalent to that of the commercially available transfection agent Lipofectamine® 2000, but with decreased cytotoxicity. The MnHAP nanoparticles were also able to deliver siRNA for silencing of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in BEL-7402 cells, which supports that MnHAP might be a promising non-viral vector for biomedical research and gene delivery.

Effect of a hypoxic microenvironment after radiofrequency ablation on residual hepatocellular cell migration and invasion

Clinical observations have shown that the boundary of tumor ablation is often less than safe border and that the use of radiofrequency ablation (RFA) in the treatment of hepatocellular carcinoma (HCC) may probably accelerate its recurrence and metastasis. RFA can cause the formation of a transition zone between normal liver tissues and necrotic coagulation, where blood stagnation and thrombosis expose residual cancer cells to a hypoxic microenvironment. As the blocked vessels are slowly reperfused, the oxygen supply is gradually restored. Here, HCC cells underwent heat treatment and were cultured under hypoxic conditions to mimic the aforementioned situation, and morphological changes were observed in the surviving cells. Compared with their parental cells, hypoxic HCC cells showed changes that include enhanced invasive, metastatic, and chemoresistant abilities as well as mesenchymal characteristics. There was also a higher percentage of stem‐like cells. However, either improving the hypoxic microenvironment or silencing hypoxia inducible factor (HIF)‐1α signaling significantly reduced the invasive, metastatic, and chemoresistant potential and reversed the epithelial‐mesenchymal transition to varying degrees. Together, these results indicated that a sustained hypoxic microenvironment after RFA may exert a negative impact on the prognosis of HCC patients, and minimizing exposure to a hypoxic microenvironment and targeting HIF‐1α signaling might be effective strategies for patients who experience insufficient RFA therapy.