Tele-Mentored Handheld Ultrasound System for General Practitioners: A Prospective, Descriptive Study in Remote and Rural Communities.

BACKGROUND: Rural general practitioners (GPs) have insufficient diagnostic information to deal with complex clinical scenarios due to the inequality in medical imaging resources in rural and remote communities. The objective of this study is to explore the value of a tele-mentored handheld ultrasound (tele-HHUS) system, allowing GPs to provide ultrasound (US) services in rural and remote communities. METHODS: Overall, 708 patients underwent tele-HHUS examination between March and October 2021 and March and April 2022 across thirteen primary hospitals and two tertiary-care general hospitals. All US examinations were guided and supervised remotely in real time by US experts more than 300 km away using the tele-HHUS system. The following details were recorded: location of tele-HHUS scanning, primary complaints, clinical diagnosis, and US findings. The recommendations (referral or follow-up) based on clinical experience alone were compared with those based on clinical experience with tele-HHUS information. RESULTS: Tele-HHUS examinations were performed both in hospital settings (90.6%, 642/708) and out of hospital settings (9.4%, 66/708). Leaving aside routine physical examinations, flank pain (14.2%, 91/642) was the most common complaint in inpatients, while chest distress (12.1%, 8/66) and flank discomfort (12.1%, 8/66) were the most common complaints in out-of-hospital settings. Additionally, the referral rate increased from 5.9% to 8.3% (kappa = 0.202; p = 0.000). CONCLUSIONS: The tele-HHUS system can help rural GPs perform HHUS successfully in remote and rural communities. This novel mobile telemedicine model is valuable in resource-limited areas.

Comparison of efficacy, safety, and patient satisfaction between thermal ablation, conventional/open thyroidectomy, and endoscopic thyroidectomy for symptomatic benign thyroid nodules.

PURPOSE: Thermal ablation (TA) is a minimally invasive treatment method for symptomatic benign thyroid nodules (BTNs). This study aimed to evaluate the value of TA by comparing the efficacy, safety, and patient satisfaction with conventional/open thyroidectomy (ConT) and endoscopic thyroidectomy (ET) for symptomatic BTNs. METHODS: Patients with symptomatic BTNs who underwent ConT, ET, or TA therapy between January 2018 and January 2020 were included. Pre-operation data of the two comparisons (TA vs. ConT and TA vs. ET) was balanced using propensity score matching. The technique efficacy (volume reduction ratio ≥50%), nodule disappearance, and regrowth rate were calculated after ablation. The operation and hospitalization time, medical cost, complications, post-operative symptoms, and cosmetic scores were recorded and compared. Patient satisfaction was evaluated using a telephone survey. RESULTS: After a median 19-month follow-up (range, 12-36 months), the technique efficacy rate, nodule disappearance, and regrowth rate were 93.2% (119/129), 6.8% (10/129), and 0.8% (1/129), respectively. Operation time, hospitalization time, and medical costs were less for patients in the TA group than for patients in the ConT and ET groups (all p < 0.001). The incidence of complications, post-operative symptoms, cosmetic scores, and overall satisfaction were not significantly different among groups (all p > 0.05). Post-operative hypothyroidism was less frequent in the TA group than in the ConT and ET groups (all p < 0.05). CONCLUSIONS: Compared to ConT and ET, TA has comparable efficacy, safety, and patient satisfaction and exhibits greater protection of thyroid function for the treatment of symptomatic BTNs.

Thermal ablation and immunotherapy for hepatocellular carcinoma: Recent advances and future directions.

Hepatocellular carcinoma (HCC) is one of most common cancers that cause death in the world. Thermal ablation (TA) is an important alternative treatment method for HCC patients who are not appropriate for surgery or liver transplantation. Particularly for small and early HCCs, TA can be considered as the first-line curative treatment. However, local and distant recurrence rates are still high even though the TA equipment and technology develop rapidly. Immunotherapy is a novel systemic treatment method to enhance the anti-tumor immune response of HCC patients, which has the potential to reduce the tumor recurrence and metastasis. The combination of local TA and systemic immunotherapy for HCCs may be an ideal treatment for enhancing the efficacy of TA and controlling the recurrence. Herein we summarize the latest progress in TA, immunotherapy, and their combination for the treatment of patients with HCC and discuss the limitations and future research directions of the combined therapy.

Thermal Ablation of Benign Thyroid Nodules and Papillary Thyroid Microcarcinoma.

Due to the increasing rates of physical examination and application of advanced ultrasound machines, incidences of benign thyroid nodules (BTNs) and papillary thyroid microcarcinoma (PTMC) were dramatically up-regulated in recent years. Thermal ablation (TA) has been widely used and regarded as a safe and effective method to eliminate or reduce BTNs and recurrent low-risk PTMC. However, conclusions using TA to treat primary PTMC are controversial. Recently, several long-term and prospective studies on TA treatment of BTNs and primary PTMC have been reported. Here, we review current literatures and progress on TA treatment of BTNs and PTMC and underline the way to get the best treatment outcomes, providing a comprehensive insight into the research progresses in this field.

Three-dimensional shear wave elastography for differentiation of breast lesions: An initial study with quantitative analysis using three orthogonal planes.

OBJECTIVES: To prospectively evaluate the diagnostic performance of three-dimensional (3D) shear wave elastography (SWE) for breast lesions with quantitative stiffness information from transverse, sagittal and coronal planes. METHODS: Conventional ultrasound (US), two-dimensional (2D)-SWE and 3D-SWE were performed for 122 consecutive patients with 122 breast lesions before biopsy or surgical excision. Maximum elasticity values of Young's modulus (Emax) were recorded on 2D-SWE and three planes of 3D-SWE. Area under the receiver operating characteristic curve (AUC), sensitivity and specificity of US, 2D-SWE and 3D-SWE were evaluated. Two combined sets (i.e., BI-RADS and 2D-SWE; BI-RADS and 3D-SWE) were compared in AUC. Observer consistency was also evaluated. RESULTS: On 3D-SWE, the AUC and sensitivity of sagittal plane were significantly higher than those of transverse and coronal planes (both P < 0.05). Compared with BI-RADS alone, both combined sets had significantly (P < 0.05) higher AUCs and specificities, whereas, the two combined sets showed no significant difference in AUC (P > 0.05). However, the combined set of BI-RADS and sagittal plane of 3D-SWE had significantly higher sensitivity than the combined set of BI-RADS and 2D-SWE. CONCLUSIONS: The sagittal plane shows the best diagnostic performance among 3D-SWE. The combination of BI-RADS and 3D-SWE is a useful tool for predicting breast malignant lesions in comparison with BI-RADS alone.

A two-stage multi-view learning framework based computer-aided diagnosis of liver tumors with contrast enhanced ultrasound images.

OBJECTIVE: With the fast development of artificial intelligence techniques, we proposed a novel two-stage multi-view learning framework for the contrast-enhanced ultrasound (CEUS) based computer-aided diagnosis for liver tumors, which adopted only three typical CEUS images selected from the arterial phase, portal venous phase and late phase. MATERIALS AND METHODS: In the first stage, the deep canonical correlation analysis (DCCA) was performed on three image pairs between the arterial and portal venous phases, arterial and delayed phases, and portal venous and delayed phases respectively, which then generated total six-view features. While in the second stage, these multi-view features were then fed to a multiple kernel learning (MKL) based classifier to further promote the diagnosis result. Two MKL classification algorithms were evaluated in this MKL-based classification framework. We evaluated proposed DCCA-MKL framework on 93 lesions (47 malignant cancers vs. 46 benign tumors). RESULTS: The proposed DCCA-MKL framework achieved the mean classification accuracy, sensitivity, specificity, Youden index, false positive rate, and false negative rate of 90.41 ± 5.80%, 93.56 ± 5.90%, 86.89 ± 9.38%, 79.44 ± 11.83%, 13.11 ± 9.38% and 6.44 ± 5.90%, respectively, by soft margin MKL classifier. CONCLUSION: The experimental results indicate that the proposed DCCA-MKL framework achieves best performance for discriminating benign liver tumors from malignant liver cancers. Moreover, it is also proved that the three-phase CEUS image based CAD is feasible for liver tumors with the proposed DCCA-MKL framework.

Complex cystic and solid breast lesions: Diagnostic performance of conventional ultrasound, strain imaging and point shear wave speed measurement.

OBJECTIVE: To assess the performance of conventional high frequency ultrasound (US) and US elastography in diagnosis of complex cystic and solid breast lesions. METHODS: Ninety three lesions in 93 patients underwent conventional US and US elastography, including strain elastography, acoustic radiation force impulse (ARFI) imaging, and point shear wave speed (SWS) measurement. RESULTS: Pathological examination revealed 31 (33.3%) of the 93 lesions were malignant and the remaining 62 (66.7%) were benign. Multivariate analysis showed that elder patient (OR: 25.301), internal vascularity (OR: 4.518), and not circumscribed margin (OR: 3.813) were independent predictors for malignancy, while predominately cystic lesions (OR: 0.178) was a predictor for benign lesions (all p < 0.05). Invalid SWS measurement was occurred in 19 of 31 (61.3%) malignant lesions and 16 of 62 (25.8%) benign lesions, respectively (p < 0.05). The mean SWS value for malignant lesions was significantly lower than that for benign ones, being 1.60±0.63 m/s (range, 0.68-2.70 m/s) versus 2.33±0.77 m/s (range, 0.67-3.97 m/s) (p < 0.05). Areas under the ROC curve (Azs) for Breast Imaging Reporting and Data System (BI-RADS) assessment, strain elasticity score, ARFI imaging and valid point SWS measurement were 0.844, 0.734, 0.763 and 0.778,respectively. CONCLUSIONS: US BI-RADS category, strain elastography score, ARFI imaging patterns and point SWS measurement are useful for malignancy prediction of complex cystic and solid breast lesions. The result that SWS for malignant lesions is lower than benign one should be carefully interpreted since invalid SWS measurement is excluded for analysis. The true stiffness of malignant cystic and solid lesions should be further evaluated with a new generation of two-dimensional SWS imaging.

Assessment of Virtual Touch Tissue Imaging Quantification and the Ultrasound Thyroid Imaging Reporting and Data System in Patients With Thyroid Nodules Referred for Biopsy.

OBJECTIVES: To evaluate the diagnostic performance of Virtual Touch tissue imaging quantification (VTIQ; Siemens Medical Solutions, Mountain View, CA) in combination with the Thyroid Imaging Reporting and Data System (TI-RADS) for assessing thyroid nodules referred for biopsy. METHODS: A total of 197 surgically or cytologically proven thyroid nodules in 187 patients were included. Nodules evaluated by conventional ultrasound (US) and VTIQ examinations were classified into US TI-RADS categories. The shear wave velocity (SWV) on VTIQ was assessed, and the cutoff value was obtained from a receiver operating characteristic curve analysis. Diagnostic performances of conventional US, VTIQ, and their combination were compared. RESULTS: There were 134 benign and 63 malignant nodules. The sensitivity and specificity for the US TI-RADS were 98.4% and 20.1%, respectively. The areas under the receiver operating characteristic curves for the mean, maximum, minimum, and ratio of the SWV were 0.818, 0.805, 0.799, and 0.728. With a cutoff value of 2.90 m/s, the sensitivity and specificity of the mean SWV were 71.4% and 82.8%. By applying this value or less as a standard for downgrading TI-RADS category 4a to category 3 lesions, the specificity significantly rose from 20.1% to 47.0% (P < .001) without a loss of sensitivity. CONCLUSIONS: The additional application of VTIQ can improve the specificity of the TI-RADS for evaluating thyroid nodules without a loss of sensitivity.

Malignancy risk stratification of thyroid nodules: comparisons of four ultrasound Thyroid Imaging Reporting and Data Systems in surgically resected nodules.

To compare the efficiency of four different ultrasound (US) Thyroid Imaging Reporting and Data Systems (TI-RADS) in malignancy risk stratification in surgically resected thyroid nodules (TNs). The study included 547 benign TNs and 464 malignant TNs. US images of the TNs were retrospectively reviewed and categorized according to the TI-RADSs published by Horvath E et al. (TI-RADS H), Park et al. (TI-RADS P), Kwak et al. (TI-RADS K) and Russ et al. (TI-RADS R). The diagnostic performances for the four TI-RADSs were then compared. At multivariate analysis, among the suspicious US features, marked hypoechogenicity was the most significant independent predictor for malignancy (OR: 15.344, 95% CI: 5.313-44.313) (P < 0.05). Higher sensitivity was seen in TI-RADS H, TI-RADS K, TI-RADS R comparing with TI-RADS P (P < 0.05 for all), whereas the specificity, accuracy and area under the ROC curve (Az) of TI-RADS P were the highest (all P < 0.05). Higher specificity, accuracy and Az were seen in TI-RADS K compared with TI-RADS R (P = 0.003). With its higher sensitivity, TI-RADS K, a simple predictive model, is practical and convenient for the management of TNs in clinical practice. The study indicates that there is a good concordance between TI-RADS categories and histopathology.

Quality Measurement of Two-dimensional Shear Wave Speed Imaging for Breast Lesions: the Associated Factors and the Impact to Diagnostic Performance.

This study aimed to identify the associated factors for quality measurement (QM) of shear wave speed (SWS) imaging and to validate the additional value of QM in the diagnosis of breast lesions. From September 2014 to February 2015, conventional ultrasound and SWS imaging were performed in 338 women with 361 breast lesions. Binary logistic regression was used to identify associated factors for QM. Sensitivity, specificity and the area under receiver operating characteristic (ROC) curve (AUC) among maximum SWS (SWS max ), QM and SWS max plus QM (SWS max +QM) were compared to validate additional value of QM. Pathology confirmed 263 (72.9%) benign lesions and 98 (27.1%) malignancies. Maximum depth (Odds ratio [OR]: 1.398) and posterior features (OR: 1.206) were identified as independent associated factors for QM. Compared with SWS max and QM, the sensitivity of SWS max +QM increased from 67.3%, 64.3% to 83.7% whereas the specificity decreased from 90.5%, 72.6% to 65.4% (all P < 0.05). SWS max had the highest AUC in comparison with QM and SWS max +QM (0.849 vs. 0.685 vs. 0.745; P < 0.05). QM for breast lesions is associated with maximum depth and posterior features. Adding QM to SWS max is useful for breast cancer screening and SWS max alone is useful for breast cancer differentiation.

Ablative safety margin depicted by fusion imaging with post-treatment contrast-enhanced ultrasound and pre-treatment CECT/CEMRI after radiofrequency ablation for liver cancers.

OBJECTIVE: To evaluate the value of fusion imaging with post-treatment contrast-enhanced ultrasound (CEUS) and pre-treatment contrast-enhanced CT/MRI (CECT/CEMRI) in evaluating ablative safety margin after percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) for liver cancers. METHODS: 34 consecutive patients with 47 liver lesions who had undergone RFA were included. Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI was carried out to evaluate local treatment response and ablative safety margin within 1-3 days after RFA. The minimal ablative safety margins of the ablation zones were recorded. The complete response (CR) rate was calculated with reference to CECT/CEMRI results 1 month after RFA. The local tumour progression (LTP) was also recorded. RESULTS: Of the 47 ablation zones, 47 (100%) were clearly depicted with CEUS-CECT/CEMRI fusion imaging, 36 (76.6%) with US-CECT/CEMRI fusion imaging and 21 (44.7%) with conventional US (both p < 0.001). The minimal ablative safety margins were great than or equal to 5 mm in 28 ablation zones, between 0 and 5 mm in 15, and less than 0 mm in 4. For the four lesions without enough ablative safety margin, three were referred to follow-up because CEUS showed larger ablation zones than pre-treatment lesions and the remaining lesion was subject to additional RFA 5 days after the first RFA. The CR rate was 95.7% (45/47) with reference to CECT/CEMRI results 1 month after RFA. During 2 to 34 months follow-up, LTP was found in two (4.4%) of 45 lesions with CR. Insufficient ablative safety margin was more commonly found in those lesions with LTP than those without LTP (1/4 vs 1/43, p < 0.001). CONCLUSION: Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI can depict the ablative safety margin accurately after RFA. Inadequate ablative safety margin is associated with LTP. Depiction of ablative safety margin by fusion imaging after ablation might be considered as a routine procedure to assess the treatment response of RFA. Advances in knowledge: Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI is an effective method to evaluate the ablative safety margin early after RFA. Therefore, it should be recommended to be used as a routine procedure after RFA for liver cancers.

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.

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.

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.

Comparison of fine needle aspiration and non-aspiration cytology for diagnosis of thyroid nodules: A prospective, randomized, and controlled trial.

OBJECTIVES: To compare the sampling efficiency and diagnostic performance of ultrasound (US)-guided fine-needle aspiration cytology (FNAC) and fine-needle non-aspiration cytology (FNNAC) for thyroid nodules. MATERIALS AND METHODS: 629 thyroid nodules in 629 cases (477 females, 152 males) were randomly subjected to FNAC or FNNAC from Jun 2014 to Feb 2015. Diagnostic performance was calculated in reference to the histological findings or follow-up results. RESULTS: 629 patients (152 men, 477 women) with 629 thyroid nodules were enrolled in the study. Pathological results were obtained in 173 nodules and benign nodules at FNA with more than six months' follow-up were found in 65 nodules. Tumor size for FNAC ranges from 3.0 to 51.0 mm (mean±SD; 10.2±6.9 mm); whereas FNNAC (2.0-43.0 mm; 11.9±7.7 mm). Non-diagnostic results were found in 7.59% (24/316) of FNNAC procedures and 7.59% (25/313) of FNAC (P > 0.05). Determinate and indeterminate results were found in 50.63% (160/316) and 41.77% (132/316) of FNNAC procedures, whereas 58.15% (182/313) and 33.87% (106/313) of FNAC (P < 0.05). In order to obtain determinate cytological results, FNAC might be more suitable than FNNAC for diagnosis of nodules with hypovascularity (51.38% vs. 41.78%, P < 0.05) and macrocalcifications (9.72% vs. 6.50%, P < 0.05). No US and Color-Doppler US characteristics, such as the presence of hypervascularity (P > 0.05), microcalcifications (P > 0.05), internal component (P > 0.05), or size(P > 0.05), were significantly different to obtain determinate cytological results between the FNAC and FNNAC groups. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of FNAC and FNNAC were as follows: 96.67% vs. 100%, 89.74% vs. 96.5%, 87.88% vs. 96.97%, 97.22% vs. 100%, 92.75% vs.98.36%, respectively (all P > 0.05). CONCLUSIONS: Both FNAC and FNNAC are effective for diagnosis of thyroid nodules. However, FNAC is more effective than FNNAC to acquire determinate cytological results for nodules which US present hypovascularity and macrocalcifications.

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.

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.

Quality measurement on shear wave speed imaging: diagnostic value in differentiation of thyroid malignancy and the associated factors.

To evaluate the associated factors for quality measurement (QM) on shear wave speed (SWS) imaging and the additional value of QM for differentiation of thyroid nodules. A consecutive series of 238 patients with 254 thyroid nodules were enrolled. They were all evaluated by conventional ultrasound and SWS imaging and were finally proven pathologically. QM was used to assess whether SWS propagation was authentic and was classified as high QM and Low QM. Twelve variables were analyzed to evaluate the associated factors for QM using binary logistic regression. Receiver operating characteristic (ROC) curve was plotted on SWS and SWS+QM. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and area under ROC curve (AUC) were calculated. The study included 170 benign thyroid nodules (160 high QM and 10 low QM) and 84 malignant thyroid nodules (56 high QM and 28 low QM) (P < 0.001). The mean SWS of benign and malignant nodules were 2.51 ± 0.47 m/s and 3.43 ± 1.21 m/s respectively (P < 0.001). The sensitivities, specificities, PPVs, NPVs, accuracies and AUCs were 77.4%, 80.0%, 65.7%, 87.7%, 79.1%, 0.82 for SWS alone with SWS ≥ 2.78 m/s; 33.3-34.5%, 91.2-94.1%, 65.9-73.7%, 73.8-74.1%, 72.4-74.0%, 0.63-0.64 for QM alone and 84.5-85.7%, 72.4-75.9%, 60.5-63.4%, 90.8-91.0%, 76.8-78.7%, 0.79-0.80 for SWS+QM. Nodule depth was identified to be the strongest associated factor for QM of SWS, followed by malignancy and SWS. In conclusion, QM for thyroid nodule is associated with nodule depth, malignancy, and SWS. QM improves the specificity in comparison with SWS alone, whereas SWS+QM does not improve the overall diagnostic performance.

Virtual Touch Tissue Imaging and Quantification in the Evaluation of Thyroid Nodules.

OBJECTIVES: To investigate the diagnostic performance of a 2-dimensional shear wave elastographic technique (Virtual Touch tissue imaging and quantification [VTIQ]; Siemens Medical Solutions, Mountain View, CA) for predicting thyroid malignancy. METHODS: A total of 302 thyroid nodules underwent conventional sonography and VTIQ before fine-needle aspiration examination or surgery. Compared with histopathologic or cytologic results in combination with follow-up, the diagnostic performance of various shear wave speed (SWS) indices (minimum [SWSmin ], maximum [SWSmax ], and mean [SWSmean ]) on VTIQ as well as conventional sonographic features for predicting thyroid malignancy was evaluated in all of the nodules. RESULTS: Sixty-five malignant and 237 benign thyroid nodules were histopathologically or cytologically confirmed. All SWS indices on VTIQ were lower in benign nodules than thyroid malignancy (all P < .001). For discrimination between malignant and benign nodules, all VTIQ SWS indices were better than conventional sonographic features, such as a solid component, a taller-than-wide shape, microcalcification, a poorly defined margin and hypoechogenicity, in predicting thyroid malignancy (all P < .05). By applying a cutoff SWSmean value of 2.60 m/s, VTIQ achieved sensitivity and negative predictive values of 84.6% and 94.3%, respectively, for differentiating nodules. The areas under the receiver operating characteristic curve of SWSmax (0.862 versus 0.717), SWSmin (0.866 versus 0.717), and SWSmean (0.891 versus 0.725) for nodules larger than 10 mm were higher than those for nodules of 10 mm or smaller (all P < .05). Interoperator and intraoperator reproducibility was proven to be excellent, with all interclass correlation coefficient values higher than 0.80 (range, 0.813-0.905) CONCLUSIONS: Virtual Touch tissue imaging and quantification is a useful and reproducible tool for predicting thyroid malignancy.

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.