Chong-Ke Zhao

Parametric imaging with contrast-enhanced ultrasound for differentiating hepatocellular carcinoma from metastatic liver cancer

AIM To evaluate the diagnostic performance of parametric imaging with contrast-enhanced ultrasound(CEUS) for differentiating hepatocellular carcinoma(HCC) from metastatic liver cancer(MLC). METHODS 30 HCCs (mean diameter, 3.6±1.3 cm; range, 2.1-5.0 cm) and 30 MLCs (mean diameter, 2.8±1.5 cm; range, 1.2-5.0 cm) pathologically diagnosed or confirmed by clinical criteria that underwent CEUS were randomly included. CEUS was carried out using a multifrequency transducer (2-4 MHz) and a bolus injection of 2.4 mL SonoVue. The CEUS clips of the targeted lesion were recorded continuously for 6 minutes. By analyzing CEUS clips, parametric image could be obtained using the SonoLiver® software automatically. Quantitative parameters were compared between HCC and MLC groups. Receiver operating characteristic (ROC) curve analysis was further performed on parameters with significant difference between two groups. RESULTS On parametric imaging, the maximum intensity, rise time, time to peak, mean transit time and washout time for HCC and MLC were 185.6±148.0 vs. 95.2±58.6 (P = 0.003), 25.7±6.3 s vs. 23.8±8.8 s (P = 0.341), 30.7±7.9 s vs. 27.8±10.5 s (P = 0.246), 90.2±45.7 s vs. 89.3±40.3 s (P = 0.805), 63.4±29.5 s vs. 37.2±33.8 s (P = 0.005), respectively. ROC analysis was further performed for washout time and it showed a cut-off point of 43.765 s for the differentiation between HCC and MLC, with the AUC value of 0.780 (95% CI: 0.646-0.914). The corresponding diagnostic specificity, sensitivity and accuracy were 72.0%, 84.6% and 78.4% respectively. CONCLUSIONS Parametric imaging of CEUS can display perfusion effects of HCC and MLC objectively and visually and washout time may serve as a useful parameter on the differential diagnosis between HCC and MLC.

Two-dimensional shear wave elastography of breast lesions: Comparison of two different systems

OBJECTIVE To evaluate the diagnostic performance of two different shear wave elastography (SWE) techniques in distinguishing malignant breast lesions from benign ones. MATERIALS AND METHODS From March 2016 to May 2016, a total of 153 breast lesions (mean diameter, 16.8 mm±10.5; range 4.1-90.0 mm) in 153 patients (mean age, 46.4 years±15.1; age range 20-86 years) were separately performed by two different SWE techniques (i.e. T-SWE, Aplio500, Toshiba Medical System, Tochigi, Japan; and S-SWE, the Aixplorer US system, SuperSonic Imagine, Provence, France). The maximum (Emax), mean (Emean) and standard deviation (ESD) of elasticity modulus values in T-SWE and S-SWE were analyzed. All the lesions were confirmed by ultrasound (US)-guided core needle biopsy (n = 26), surgery (n = 122), or both (n = 5), with pathological results as the gold standard. The areas under the receiver operating characteristic curves (AUROCs) were calculated. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV) were calculated to assess the diagnostic performance between T-SWE and S-SWE. Operator consistency was also evaluated. RESULTS Among the 153 lesions, 41 (26.8%) were malignant and 112 (73.2%) were benign. Emax (T-SWE: 40.10±37.14 kPa vs. 118.78±34.41 kPa; S-SWE: 41.22±22.54 kPa vs. 134.77±60.51 kPa), Emean (T-SWE: 19.75±16.31 kPa vs. 52.93±25.75 kPa; S-SWE: 20.95±10.98 kPa vs. 55.95±22.42 kPa) and ESD (T-SWE: 9.00±8.55 kPa vs. 38.44±12.30 kPa; S-SWE: 8.17±6.14 kPa vs. 29.34±13.88 kPa) showed statistical differences in distinguishing malignant lesions from benign ones both in T-SWE and S-SWE (all p < 0.05). In T-SWE, the diagnostic performance of ESD was the highest (AUROC = 0.958), followed by Emax (AUROC = 0.909; p = 0.001 in comparison with ESD) and Emean (AUROC = 0.892; p < 0.001 in comparison with ESD), while in S-SWE, the diagnostic performance of Emax was the highest (AUROC = 0.967), followed by ESD (AUROC = 0.962, p > 0.05 in comparison with Emax) and Emean (AUROC = 0.930, p = 0.034 in comparison with Emax). AUROC-max (T-SWE: 0.909 vs. S-SWE 0.967), AUROC-mean (T-SWE: 0.892 vs. S-SWE 0.930) and AUROC-SD (T-SWE: 0.958 vs. S-SWE 0.962) showed no significant difference between T-SWE and S-SWE (all p > 0.05). The intra-class correlation coefficients (ICC) of the intra-operator consistency and inter-operator consistency respectively were 0.961 and 0.898 in T-SWE, while 0.954 and 0.897 in S-SWE. CONCLUSION T-SWE and S-SWE are equivalent for distinguishing the breast lesions. In T-SWE, ESD had the best diagnostic performance, while in S-SWE, Emax had the best diagnostic performance.

First experience of comparisons between two different shear wave speed imaging systems in differentiating malignant from benign thyroid nodules

OBJECTIVE The purpose of this study was to comparatively evaluate the two different shear wave speed (SWS) imaging systems of Toshiba shear wave elastography (T-SWE) and SuperSonic SWE (S-SWE) in distinguishing malignant from benign thyroid nodules (TNs). MATERIALS AND METHODS 140 patients with 140 focal TNs were enrolled and underwent T-SWE and S-SWE before fine-needle aspiration (FNA) biopsy or surgery. SWE indices of mean, standard deviation and maximum values (E-mean, E-SD and E-max) of elastic modulus in TNs were measured on a color-coded mapping. The receiver operating characteristic (ROC) curve was performed to assess the diagnostic performance. RESULTS Of the 140 nodules, 47 were thyroid carcinomas and 93 were benign. Areas under the receiver operating characteristic curve (AUC) were the highest with E-max among the three SWE parameters both for T-SWE and S-SWE (0.816 and 0.799). The most accurate cut-off values, sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 26.6 kPa versus 42.9 kPa, 83.0% versus 63.8%, 68.8% versus 88.2%, 72.9% versus 80.0%, 56.5% versus 73.2% and 88.7% versus 82.8% with E-max for T-SWE and S-SWE, respectively. Among these comparisons, the sensitivity in T-SWE was statistically higher than S-SWE (83.0% versus 63.8%, p = 0.022), whereas specificity was statistically lower than S-SWE (68.8% versus 88.2%, p < 0.001). CONCLUSION T-SWE is equal to S-SWE with comparable and promising results for diagnosis of TNs. In clinical using, the selection of E-max should be recommended both for T-SWE and S-SWE.

Qualitative and quantitative analysis with a novel shear wave speed imaging for differential diagnosis of breast lesions

To evaluate the diagnostic performance of a new two-dimensional shear wave speed (SWS) imaging (i.e. Toshiba shear wave elastography, T-SWE) in differential diagnosis of breast lesions. 225 pathologically confirmed breast lesions in 218 patients were subject to conventional ultrasound and T-SWE examinations. The mean, standard deviation and ratio of SWS values (m/s) and elastic modulus (KPa) on T-SWE were computed. Besides, the 2D elastic images were classified into four color patterns. The area under the receiver operating characteristic (AUROC) curve analysis was performed to evaluate the diagnostic performance of T-SWE in differentiation of breast lesions. Compared with other quantitative T-SWE parameters, mean value expressed in KPa had the highest AUROC value (AUROC = 0.943), with corresponding cut-off value of 36.1 KPa, sensitivity of 85.1%, specificity of 96.6%, accuracy of 94.2%, PPV of 87.0%, and NPV of 96.1%. The AUROC of qualitative color patterns in this study obtained the best performance (AUROC = 0.957), while the differences were not significant except for that of Eratio expressed in m/s (AUROC = 0.863) (P = 0.03). In summary, qualitative color patterns of T-SWE obtained the best performance in all parameters, while mean stiffness (36.05 KPa) provided the best diagnostic performance in the quantitative parameters.

Risk stratification of thyroid nodules with Bethesda category III results on fine-needle aspiration cytology: The additional value of acoustic radiation force impulse elastography

To assess the value of conventional ultrasound, conventional strain elastography (CSE) and acoustic radiation force impulse (ARFI) elastography in differentiating likelihood of malignancy for Bethesda category III thyroid nodules. 103 thyroid nodules with Bethesda category III results on fine-needle aspiration cytology (FNAC) in 103 patients were included and all were pathologically confirmed after surgery. Conventional ultrasound, CSE and ARFI elastography including ARFI imaging and point shear wave speed (SWS) measurement were performed. Univariate and multivariate analyses were performed to identify the independent factors associated with malignancy. Area under the receiver operating characteristic curve (Az) was calculated to assess the diagnostic performance. Pathologically, 65 nodules were benign and 38 were malignant. Significant differences were found between benign and malignant nodules in ARFI. The cut-off points were ARFI imaging grade ≥ 4, SWS > 2.94 m/s and SWS ratio > 1.09, respectively. ARFI imaging (Az: 0.861) had the highest diagnostic performance to differentiate malignant from benign nodules, following by conventional ultrasound (Az: 0.606 - 0.744), CSE (Az: 0.660) and point SWS measurement (Az: 0.725 - 0.735). Multivariate logistic regression analysis showed that ARFI imaging grade ≥ 4 was the most significant independent predictor. The combination of ARFI imaging with point SWS measurement significantly improved the specificity (100% vs. 80.0%) and positive predictive value (100 % vs. 72.9%) in comparison with ARFI imaging alone. ARFI elastography is a useful tool in differentiating malignant from benign thyroid nodules with Bethesda category III results on FNAC.

Factors associated with initial incomplete ablation for benign thyroid nodules after radiofrequency ablation: First results of CEUS evaluation

OBJECTIVE To assess the factors associated with initial incomplete ablation (ICA) after radiofrequency ablation for benign thyroid nodules (BTNs). MATERIALS AND METHODS 69 BTNs (mean volume 6.35±5.66 ml, range 1.00-25.04 ml) confirmed by fine-needle aspiration cytology (FNAC) in fifty-four patients were treated with ultrasound-guided percutaneous radiofrequency ablation (RFA) and the local treatment efficacy was immediately assessed by intra-procedural contrast-enhanced ultrasound (CEUS). The RFA was performed with a bipolar electrode (CelonProSurge 150-T20, output power: 20 W). CEUS was performed with a second generation contrast agent under low acoustic power (i.e. coded phase inversion, CPI). Characteristics of clinical factors, findings on conventional gray-scale ultrasound, color-Doppler ultrasound, and CEUS were evaluated preoperatively. Factors associated with initial ICA and initial ICA patterns on CEUS were assessed. Volume reduction ratios (VRRs) of ICA nodules were compared with those with complete ablation (CA). RESULTS The RFA procedures were accomplished with a mean ablation time and mean total energy deposition of 11.13±3.39 min (range, 5.38-22.13 min) and 12612±4466 J (range, 6310-26130 J) respectively. CEUS detected initial ICA in 21 of 69 (30.8%) BTNs and 16 (76.2%) of the 21 BTNs with initial ICA achieved CA after additional RFA, leading to a final CA rate of 92.8% (64/69). The factors associated with initial ICA were predominantly solid nodule, nodule close to danger triangle area, nodule close to carotid artery, and peripheral blood flow on color-Doppler ultrasound (all P < 0.05). The mean VRRs of all BTNs were 23.4%, 54.4% and 81.9% at the 1-, 3- and 6-month follow-up, respectively. All BTNs achieved therapeutic success in this series in that all had VRRs of >50% at the 6-month follow-up, among which 7 nodules (10.1%) had VRRs of >90%. There were significant differences in VRRs between ICA nodules and CA nodules at the 3- and 6-month follow-up (all P < 0.05). CONCLUSION The factors associated with initial ICA after RFA for BTNs were predominantly solid nodules, nodule close to danger triangle area, nodule close to carotid artery, and peripheral blood flow on color-Doppler ultrasound. CEUS assists quick treatment response evaluation and facilitates subsequent additional RFA and final CA of the nodules. Nodules with CA achieve a better outcome in terms of VRR in comparison with those with ICA.

Comparison of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Toshiba shear wave elastography (T-SWE) in diagnosis of thyroid nodules: Initial experience

OBJECTIVE The aim of this study was to compare the diagnostic performance of two different 2D shear wave speed imaging techniques of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Toshiba shear wave elastography (T-SWE) in predicting malignant thyroid nodules (TNs). MATERIALS AND METHODS 75 TNs in 75 patients which were subject to both VTIQ and T-SWE examinations were enrolled and analyzed. Shear wave speed (SWS) values on VTIQ and T-SWE were computed (SWS_max, min, mean and median). Area under the receiver operating characteristic (AUROC) curve was obtained to assess the diagnostic performance. RESULTS The AUROC for VTIQ was the highest with SWS_min whereas for T-SWE was SWS_max (0.774 versus 0.851; p > 0.05). The AUROC, sensitivity and negative predictive value (NPV) corresponding to SWS_max for VTIQ were significantly lower than those for T-SWE (0.717 versus 0.851, 61.5% versus 92.3% and 78.7% versus 94.3%; all p < 0.05). However, no significant differences were found between AUROC with SWS_min, SWS_mean, or SWS_median for VTIQ and SWS_max for T-SWE (all p > 0.05). CONCLUSION In general, VTIQ is equal to T-SWE for diagnosis of TNs. In the clinical practice, the selection of SWS_max should be avoided in VTIQ whereas should be selected in T-SWE.

Virtual touch tissue imaging and quantification (VTIQ) in the evaluation of thyroid nodules: the associated factors leading to misdiagnosis

To evaluate the associated factors leading to misdiagnosis with VTIQ for differentiation between benign from malignant thyroid nodules (TNs). The study included 238 benign TNs and 150 malignant TNs. Conventional ultrasound (US) features and VTIQ parameters were obtained and compared with the reference standard of histopathological and/or cytological results. Binary logistic regression analysis was performed to select independent variables leading to misdiagnosis. The maximum shear wave speed (SWS) (SWS-max), mean SWS (SWS-mean), SWS-ratio and standard deviation of SWS (SWS-SD) were significantly higher for malignant TNs compared with benign TNs (all P < 0.001). SWS-mean achieved the highest diagnostic performance with a cut-off value of 3.15 m/s. False positive rate was 13.4% (32/238) while false negative rate was 35.3% (53/150). Intranodular calcification (OR: 1.715) was significantly associated with false positive VTIQ findings, while nodule size (OR: 0.936) and echotexture of the thyroid gland (OR: 0.033) were negatively associated with them. Nodule depth (OR: 0.881) and TI-RADS category (OR: 0.563) were negatively associated with false negative VTIQ findings. These US characteristic of TNs should be taken into consideration when interpreting the results of VTIQ examinations.

The diagnostic performance of shear wave speed (SWS) imaging for thyroid nodules with elasticity modulus and SWS measurement

To evaluate the diagnostic performance of a new technique of shear wave speed (SWS) imaging for the diagnosis of thyroid nodule with elasticity modulus and SWS measurement. 322 thyroid nodules in 322 patients (216 benign nodules, 106 malignant nodules) were included in this study. All the nodules received conventional ultrasound (US) and SWS imaging (Aplio500, Toshiba Medical Systems, Japan) before fine-needle aspiration (FNA) and/or surgery. The values of E-max and E-mean with elastic modulus (61.27 ± 36.31 kPa and 31.89 ± 19.11 kPa) or SWS (4.45 ± 1.49 m/s and 3.26 ± 2.71 m/s) in malignant nodules were significantly higher than those in benign lesions (29.18 ± 18.62 kPa and 15.85 ± 6.96 kPa, or 2.98 ± 0.85 m/s and 2.19 ± 0.42 m/s, all P < 0.001). No significant differences in area under the curve (AUC) between the SWS imaging parameters were found (all P > 0.05). In multivariate logistic regression analysis, E-max (m/s) with SWS was identified to be the strongest independent predictor for malignant nodules (odds ratio [OR] = 16.760), followed by poorly-defined margin (OR = 7.792), taller-than-wide shape (OR = 3.160), micro-calcification (OR = 2.422), and E-max (kPa) with elastic modulus (OR = 0.914). The AUC was 0.813 for E-max with SWS (m/s) and 0.796 for E-max with elastic modulus (kPa). With cut-off SWS value of 3.52 m/s in E-max, sensitivity of 69.8%, specificity of 81.5%, and accuracy of 77.6% were achieved. SWS imaging is a valuable tool in predicting thyroid malignancy. E-max with SWS measurement is the strongest independent predictor for thyroid malignancy.

Thyroid imaging reporting and data system in assessment of cytological Bethesda Category III thyroid nodules

OBJECTIVE To assess the usefulness of thyroid imaging reporting and data system (TI-RADS) for cytological Bethesda Category III thyroid nodules (TNs). METHODS This retrospective study included 121 patients with 121 TNs classified as Bethesda Category III at fine needle aspiration (FNA) cytology and thereafter underwent surgery. The TNs were classified according to US TI-RADS category and the malignancy risk of each category was calculated. RESULTS Surgical pathology confirmed 43 (35.5%) malignant and 78 (64.5%) benign TNs. The malignancy risks of categories 3, 4a, 4b, 4c, and 5 TNs were 0%, 4.0%, 12.5%, 62.2%, and 100%, respectively. For those >10 mm (n = 55), the malignancy risks were 0%, 6.2%, 12.5%, 73.3%, and 100%, respectively, whereas for those ≤10 mm (n = 66), the risks were 0%, 0%, 12.5%, 56.7%, and 100%, respectively. CONCLUSION Bethesda Category III TNs without suspicious US features or those ≤10 mm with only one suspicious US feature can be followed up with US.