To evaluate the therapeutic efficacy and safety of ultrasound-guided percutaneous bipolar radiofrequency ablation (BRFA) of benign thyroid nodules by comparison with a matched untreated control group. The therapeutic efficacy and safety in 35 patients who were subjected to a single session of ultrasound-guided percutaneous BRFA (Group A) for benign thyroid nodules were compared with those in 35 untreated patients (Group B) with benign nodules. The benign nature of all the nodules was confirmed by ultrasound-guided fine-needle aspiration biopsy (FNAB), and all the patients had normal thyroid functions. BRFA was performed with a bipolar electrode (CelonProSurge 150–T20) with an output power of 20 W. Nodule volume, thyroid function and clinical symptoms of all the patients were compared before treatment and during follow-up. In Group A, the BRFA procedures were completed with a mean time of 10.02 ± 3.30 min (range, 5.47–16.03 min) and with a mean total energy deposition of 10.747 ± 3704 J (range, 5510–17.770 J). The procedures were tolerated well in all the patients without causing any major complications. At the 6-month follow-up, all of the nodule volume decreased significantly (from 8.81 ± 8.66 to 1.59 ± 1.55 ml, p < 0.001) in Group A, whereas the nodule volume increased from 6.90 ± 3.77 to 7.87 ± 3.95 ml in Group B (p < 0.001). All (100%) the 35 nodules in Group A had volume reduction ratios (VRRs) of >50%, among which 3 (8.57%) had VRRs >90%. In Group A, the clinical symptoms of the patients who had symptoms before BRFA disappeared, whereas in Group B, the patients had no resolution of clinical symptoms at the 6-month follow-up. Ultrasound-guided percutaneous BRFA seems to be an effective and safe method for the treatment of benign thyroid nodules. It may gain a wide use in clinical practice. Based on the comparable efficacy and clinical symptoms between the BRFA and untreated groups, the technique of BRFA can be used as an effective and safe method for the treatment of benign thyroid nodules.

Objective:To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers.Methods:45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded.Results:On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous...

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.

Objective:To evaluate the usefulness of two-dimensional quantitative ultrasound shear-wave elastography (2D-SWE) [i.e. virtual touch imaging quantification (VTIQ)] in assessing the ablation zone after radiofrequency ablation (RFA) for ex vivo swine livers.Methods:RFA was performed in 10 pieces of fresh ex vivo swine livers with a T20 electrode needle and 20-W output power. Conventional ultrasound, conventional strain elastography (SE) and VTIQ were performed to depict the ablation zone 0 min, 10 min, 30 min and 60 min after ablation. On VTIQ, the ablation zones were evaluated qualitatively by evaluating the shear-wave velocity (SWV) map and quantitatively by measuring the SWV. The ultrasound, SE and VTIQ results were compared against gross pathological and histopathological specimens.Results:VTIQ SWV maps gave more details about the ablation zone, the central necrotic zone appeared as red, lateral necrotic zone as green and transitional zone as light green, from inner to exterior, while the peripheral una...

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.

Objective: This study aimed to develop a machine learning (ML)-based ultrasound (US) radiomics model for prediction of 6-month local treatment response (LTR) ofthermal ablation (TA) for benign thyroid nodules (BTNs). Methods: Between January 2018 and July 2021, a total of 388 patients who underwent US-guided TA in three centers were included. US radiomics features were extracted from preoperative grayscale US images and data dimensionality reduced using principal component analysis and least absolute shrinkage and selection operator. Then, support vector machine (SVM), logistic regression, a decision tree, K-nearest neighbors, and random forest were applied to selected key US radiomics features for distinguishing a volume reduction ratio (VRR) ≥50% or <50%. Factors affecting 6-month LTR were assessed using multivariate logistic regression to construct a clinical model. Receiver operating characteristic curves were plotted to compare the predictive performance between radiomics-based ML and clinical models. Results: At 6 months post-ablation, patients with VRR ≥ 50% were 75.8% (292/372) in the training and internal test cohorts and 59.4% (19/32) in the external test cohort. Finally, 10 US radiomics features were selected for analysis. Solidity was the only independent clinical predictor associated with VRR<50%. Among the five algorithms, the SVM model achieved the optimal predictive efficacy, with an area under the curve (AUC) = 0.81 in the internal test set. The AUC of the SVM-based US radiomics model was significantly higher than that of the clinical model in both internal (0.81 vs. 0.63, P< 0.05) and external test cohorts (0.77 vs. 0.54, P< 0.05). Conclusion: The SVM-based US radiomicsmodel yielded a satisfactory performance for predicting the 6-month LTR, outperforming the clinical model, and facilitating decision-making in favor of TA.