Preoperative differentiation of thyroid adenomas and thyroid carcinomas using high resolution contrast-enhanced ultrasound (CEUS)

The Utility of Contrast-Enhanced Ultrasound (CEUS) in Assessing the Risk of Malignancy in Thyroid Nodules

BACKGROUND

Ultrasonography is a primary method used in the evaluation of thyroid nodules, but no single feature of this method predicts malignancy with high accuracy. Therefore, this paper aims to assess the utility of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of thyroid nodules.

METHODS

The study group comprised 188 adult patients (155 women and 33 men) who preoperatively underwent CEUS of a thyroid nodule classified as Bethesda categories II-VI after fine-needle aspiration biopsy. During the CEUS examination, 1.5 mL of SonoVue contrast was injected intravenously, after which 15 qualitative CEUS enhancement patterns were analysed.

RESULTS

The histopathologic results comprised 65 benign thyroid nodules and 123 thyroid carcinomas. The dominant malignant CEUS features, such as hypo- and heterogeneous enhancement and slow wash-in phase, were evaluated, whereas high enhancement, ring enhancement, and a slow wash-out phase were assessed as predictors of benign lesions. Two significant combinations of B-mode and CEUS patterns were noted, namely, hypoechogenicity with heterogeneous enhancement and non-smooth margins with hypo- or iso-enhancement.

CONCLUSIONS

The preliminary results indicate that CEUS is a useful tool in assessing the risk of malignancy of thyroid lesions. The combination of the qualitative enhancement parameters and B-mode sonographic features significantly increases the method's usefulness.

Contrast-enhanced ultrasonography of the thyroid gland in healthy dogs, hypothyroid dogs and dogs with non-thyroidal illness

Diagnosis of canine hypothyroidism remains challenging, as non-thyroidal illness (NTI)-syndrome and medical treatment can influence thyroid hormone concentrations. Conventional ultrasound may give additional hints, however high interobserver variability has been described. Contrast-enhanced ultrasound (CEUS) allows detection of changes in tissue perfusion. The purpose of the present study was to assess the possible diagnostic value of CEUS regarding diagnosis of hypothyroidism. CEUS of the thyroid gland was performed in 52 healthy dogs, 16 hypothyroid dogs, and 20 NTI patients. The following perfusion parameters were calculated: Thyroid/carotid artery (TG/CA) ratios for peak enhancement (PE) and area under the curve (AUC), time to peak (TTP) and wash-in and wash-out rates (WiR, WoR) of the thyroid gland. Impact of sedation on perfusion parameters was investigated in 8 calm healthy dogs which were examined before and after sedation using midazolam and butorphanol. Significantly higher median TG/CA ratios for PE were detected for the left and right thyroid lobe in dogs with hypothyroidism (0.97/0.96) compared to healthy dogs (0.85/0.85) and dogs with NTI (0.84/0.84). AUCs were also significantly increased in hypothyroid dogs when compared to other groups. Dogs with NTI showed significantly lower WiR and WoR compared to other groups. Values for TTP were not significantly different between groups. Sedation had only impact on results of TTP which was significantly prolonged in sedated dogs. In conclusion, CEUS of the thyroid gland can provide an additional tool for diagnosis of hypothyroidism in dogs and support its differentiation from NTI. Sedation has limited impact on CEUS results.

Analysis and prediction of regrowth in benign thyroid nodules undergoing radiofrequency ablation: a retrospective study with a 5-year follow-up

OBJECTIVES

To evaluate the 5-year follow-up results of radiofrequency ablation (RFA) for benign thyroid nodules (BTNs), and construct pre- and postablation nomogram models to predict regrowth in BTNs undergoing RFA.

METHODS

According to the occurrence of regrowth, BTNs were divided into two subgroups, the regrowth group and the nonregrowth group, and the variables were compared between these two subgroups. Then, univariate and multivariate Cox regression analyzes were utilized to filter the independent prognostic factors of regrowth, which then were introduced into the pre- and postablation prognostic nomograms, respectively. The discrimination powers and prediction performances of the nomograms were appraised by receiver operating characteristic (ROC) curves and calibration charts.

RESULTS

The 5-year mean volume reduction rate was 88.80%, with a complication rate of 0.35% (7/200). Within 5 years of follow-up, the regrowth rate was 19% (38/200). Pre- and postablation prognostic nomograms were established to predict the probability of nonregrowth at 1, 3, and 5 years after RFA. The preablation nomogram included initial volume, perinodular vascularity, and high enhancement ring. The postablation nomogram incorporated total volume, perinodular vascularity, and energy applied per volume. The area under the ROC curves and concordance index values of these models were all above 0.7, indicating that the prognostic nomograms achieved satisfactory discrimination powers and prediction performances.

CONCLUSION

RFA for BTNs has long-term efficacy and safety under the influence of key techniques. The pre- and postablation nomograms constructed in the present study might facilitate clinical decision-making before RFA and for the follow-up management after RFA.

KEY POINTS

• Perinodular vascularity, rather than intranodular vascularity was an independent predictor of regrowth, both before and after the RFA procedure. • A high enhancement ring on preablation contrast-enhanced ultrasound was an independent predictor of regrowth. • Pre- and postablation nomograms might facilitate clinical decision-making before RFA and follow-up management after RFA.

VueBox® perfusion analysis of dynamic contrast enhanced ultrasound provides added value in the diagnosis of small thyroid nodules

OBJECTIVES

To explore the potential added value of dynamic contrast enhanced ultrasound (DCE-US) using VueBox® software for the diagnosis of small solid thyroid nodules (≤1.0 cm).

PATIENTS AND METHODS

This prospective study was approved by the institutional review board and it was performed at two hospitals from January 2020 to October 2020. B mode ultrasound and contrast enhanced ultrasound (CEUS) images were obtained for 79 small solid thyroid nodules (≤1.0 cm) confirmed by ultrasound-guided fine needle aspiration cytology results in 79 consecutive patients (55 women and 24 men, median age: 41 years). The CEUS time-intensity curves (TICs) of thyroid nodules and surrounding parenchyma were created by VueBox® software (Bracco, Italy). The CEUS quantitative parameters were obtained after curve fitting. The diagnostic efficiency of the diagnostic performance of CEUS and DCE-US was evaluated and compared. The weighted kappa statistic (κ) was performed to assess the interobserver agreement and consistency between the diagnosis of CEUS and DCE-US.

RESULTS

Among the 79 thyroid nodules, 56 (70.9 %) were malignant and 23 (29.1 %) were benign lesions. Hypoenhancement during the arterial phase of CEUS was associated with malignancy (P <  0.001), with an AUC of 0.705 (sensitivity 71.4 %, specificity 69.6 %). Among all CEUS quantitative parameters, the peak enhancement (PE), wash-in rate (WiR), and wash-out rate (WoR) of DCE-US in malignancies were significantly lower than those in benign nodules (P = 0.049, P = 0.046, and P = 0.020, respectively). The AUCs of PE, WiR, and WoR were 0.642 (sensitivity 65.2 %, specificity 67.9 %), 0.643 (sensitivity 43.5 %, specificity 91.1 %), and 0.667 (sensitivity 69.6 %, specificity 69.6 %) in differentiation between benign and malignant small solid thyroid nodules (≤1.0 cm), respectively. Comparing the quantitative parameters of DCE-US between small solid thyroid nodules and surrounding normal thyroid parenchyma, the PE, WiAUC, WiR, WiPI, WoAUC, WiWoAUC, and WoR of the nodules were significantly lower than those of normal thyroid tissue (P = 0.008, P <  0.001, P = 0.037, P = 0.009, P = 0.003, P = 0.002, P = 0.049, respectively). A total of 16 (20.3 %) nodules showed isoenhancement during the arterial phase of CEUS, while the median PE ratio of surrounding tissue and thyroid nodules was 1.70 (IQR: 1.33-1.89).

CONCLUSIONS

VueBox® is a helpful tool for the evaluation of dynamic microvascularization of thyroid nodules, and DCE-US using VueBox® perfusion analysis could provide added values for differential diagnosis of small solid thyroid nodules (≤1.0 cm).

The use of modified TI-RADS using contrast-enhanced ultrasound features for classification purposes in the differential diagnosis of benign and malignant thyroid nodules: A prospective and multi-center study

OBJECTIVES

To evaluate the diagnostic efficacy of a modified thyroid imaging reporting and data system (TI-RADS) in combination with contrast-enhanced ultrasound (CEUS) for differentiating between benign and malignant thyroid nodules and to assess inter-observer concordance between different observers.

METHODS

This study included 3353 patients who underwent thyroid ultrasound (US) and CEUS in ten multi-centers between September 2018 and March 2020. Based on a modified TI-RADS classification using the CEUS enhancement pattern of thyroid lesions, ten radiologists analyzed all US and CEUS examinations independently and assigned a TI-RADS category to each thyroid nodule. Pathology was the reference standard for determining the diagnostic performance (accuracy (ACC), sensitivity (SEN), specificity (SPN), positive predictive value (PPV), and negative predictive value (NPV)) of the modified TI-RADS for predicting malignant thyroid nodules. The risk of malignancy was stratified for each TI-RADS category-based on the total number of benign and malignant lesions in that category. ROC curve was used to determine the cut-off value and the area under the curve (AUC). Cohen's Kappa statistic was applied to assess the inter-observer agreement of each sonological feature and TI-RADS category for thyroid nodules.

RESULTS

The calculated malignancy risk in the modified TI-RADS categories 5, 4b, 4a, 3 and 2 nodules was 95.4%, 86.0%, 12.0%, 4.1% and 0%, respectively. The malignancy risk for the five categories was in agreement with the suggested malignancy risk. The ROC curve showed that the AUC under the ROC curve was 0.936, and the cutoff value of the modified TI-RADS classification was >TI-RADS 4a, whose SEN, ACC, PPV, NPV and SPN were 93.6%, 91.9%, 90.4%, 93.7% and 88.5% respectively. The Kappa value for taller than wide, microcalcification, marked hypoechoic, solid composition, irregular margins and enhancement pattern of CEUS was 0.94, 0.93, 0.75, 0.89, 0.86 and 0.81, respectively. There was also good agreement between the observers with regards to the modified TI-RADS classification, the Kappa value was 0.80.

CONCLUSIONS

The actual risk of malignancy according to the modified TI-RADS concurred with the suggested risk of malignancy. Inter-observer agreement for the modified TI-RADS category was good, thus suggesting that this classification was very suitable for clinical application.

ACR TI-RADS classification combined with number of nodules, halo features optimizes diagnosis and prediction of follicular thyroid cancer

OBJECTIVES

To investigate the application value of The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) category combined with other ultrasound features of nodules in distinguishing follicular thyroid carcinoma (FTC) from thyroid follicular adenoma (FTA).

METHODS

We collected and retrospectively analyzed clinical and ultrasound data for 118 and 459 patients with FTCs and FTAs, respectively, at our hospital. Next, we used ACR TI-RADS classification combined with other ultrasound features of nodules to distinguish FTC from FTA. Multivariate Logistic regression was used to screen independent risk factors for FTC, which were subsequently used to construct a nomogram for predicting FTC.

RESULTS

ACR TI-RADS categories 4 and 5, unilateral multiple nodules, and halo thickness≥2 mm were independent risk factors for FTC. ACR TI-RADS category combined with number of nodules, halo features of the nodule was a significantly better prediction model for FTC diagnosis (AUC = 0.869) than that of ACR TI-RADS classification alone (AUC = 0.756).

CONCLUTIONS

Clinicians need to pay attention to the halo of nodules when distinguishing FTA from FTC. Notably, ACR TI-RADS combined with other nodule ultrasound features has superior predictive performance in diagnosis of FTC compared to ACR TI-RADS classification alone, thus can provide an important reference value for preoperative diagnosis of FTC.

The diagnostic value of a nomogram based on multimodal ultrasonography for thyroid-nodule differentiation: A multicenter study

Objective

To establish and verify a nomogram based on multimodal ultrasonography (US) for the assessment of the malignancy risk of thyroid nodules and to explore its value in distinguishing benign from malignant thyroid nodules.

Methods

From September 2020 to December 2021, the data of 447 individuals with thyroid nodules were retrieved from the multicenter database of medical images of the National Health Commission’s Capacity Building and Continuing Education Center, which includes data from more than 20 hospitals. All patients underwent contrast-enhanced US (CEUS) and elastography before surgery or fine needle aspiration. The training set consisted of three hundred datasets from the multicenter database (excluding Zhejiang Cancer Hospital), and the external validation set consisted of 147 datasets from Zhejiang Cancer Hospital. As per the pathological results, the training set was separated into benign and malignant groups. The characteristics of the lesions in the two groups were analyzed and compared using conventional US, CEUS, and elastography score. Using multivariate logistic regression to screen independent predictive risk indicators, then a nomogram for risk assessment of malignant thyroid nodules was created. The diagnostic performance of the nomogram was assessed utilizing calibration curves and receiver operating characteristic (ROC) from the training and validation cohorts. The nomogram and The American College of Radiology Thyroid Imaging, Reporting and Data System were assessed clinically using decision curve analysis (DCA).

Results

Multivariate regression showed that irregular shape, elastography score (≥ 3), lack of ring enhancement, and unclear margin after enhancement were independent predictors of malignancy. During the training (area under the ROC [AUC]: 0.936; 95% confidence interval [CI]: 0.902–0.961) and validation (AUC: 0.902; 95% CI: 0.842–0.945) sets, the multimodal US nomogram with these four variables demonstrated good calibration and discrimination. The DCA results confirmed the good clinical applicability of the multimodal US nomogram for predicting thyroid cancer.

Conclusions

As a preoperative prediction tool, our multimodal US-based nomogram showed good ability to distinguish benign from malignant thyroid nodules.

Benefits of Contrast-Enhanced Ultrasonography to the Differential Diagnosis of TI-RADS 4-5 Thyroid Nodules

Objective

The early detection, diagnosis, and treatment of thyroid cancer are of great significance to the prognosis for patients. This study was aimed at exploring the benefits of contrast-enhanced ultrasonography (CEUS) to the differential diagnosis of thyroid nodules classified as TI-RADS class 4 or 5.

Method

A total of 46 patients with TI-RADS 4-5 thyroid nodules admitted in Peking University People's Hospital from January 2019 to January 2021 were selected to study. The sensitivity, specificity, accuracy, and positive and negative predictive values of conventional ultrasonography (US) and conventional ultrasonography combined with contrast-enhanced ultrasonography (US + CEUS) in the diagnosis of benign and malignant thyroid nodules were compared by referring to the results of the surgical pathology report, which is seen as the "gold standard" for diagnosis, followed by the construction of receiver operating characteristic curves (ROCs).

Result

Among 57 thyroid nodules, there were statistically significant differences between benign and malignant thyroid nodules in terms of echogenicity, margin characteristics, aspect ratio, and calcification (P < 0.01). In the case of CEUS, there was no statistically significant difference among contrast agent perfusion patterns in distinguishing between benign and malignant thyroid nodules (P > 0.05). However, there were statistically significant differences among different enhancement degrees, enhanced borders, and enhancement patterns. By comparing the CEUS results of TI-RADS 4-5 thyroid nodules with the results of pathology report, the malignancy rate was found to pathology report results, the malignancy rate was 53.85% in TI-RADS class 4 thyroid nodules and 100.00% in TI-RADS class 5 thyroid nodules. Among thyroid nodules diagnosed using US, 6 benign nodules were misdiagnosed as malignant and 7 malignant nodules were misdiagnosed as benign. Among those diagnosed using US + CEUS, 2 benign nodules were misdiagnosed as malignant and 2 malignant nodules were misdiagnosed as benign. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of UN + CEUS significantly outperformed those of UN alone in diagnosing thyroid nodules (P < 0.05). The ROC curve analysis showed that the area under the curve (AUC) derived from US + CEUS was 0.849, while the AUC from US was only 0.726.

Conclusion

Using US + CEUS to diagnose thyroid nodules classified as TI-RADS category 4 or 5 can further improve distinguishing between benign and malignant nodules. The CEUS is of important value to clinical applications as it can provide effective supplementary information and quantitative analysis for the differentiation between benign and malignant thyroid nodules.

Multifunctional liposome for photoacoustic/ultrasound imaging-guided chemo/photothermal retinoblastoma therapy

Retinoblastoma (RB) is a malignant intraocular neoplasm that occurs in children. Diagnosis and therapy are frequently delayed, often leading to metastasis, which necessitates effective imaging and treatment. In recent years, the use of nanoplatforms allowing both imaging and targeted treatment has attracted much attention. Herein, we report a novel nanoplatform folate-receptor (FR) targeted laser-activatable liposome termed FA-DOX-ICG-PFP@Lip, which is loaded with doxorubicin (DOX)/indocyanine green (ICG) and liquid perfluoropentane (PFP) for photoacoustic/ultrasound (PA/US) dual-modal imaging-guided chemo/photothermal RB therapy. The dual-modal imaging capability, photothermal conversion under laser irradiation, biocompatibility, and antitumor ability of these liposomes were appraised. The multifunctional liposome showed a good tumor targeting ability and was efficacious as a dual-modality contrast agent both in vivo and in vitro. When laser-irradiated, the liposome converted light energy to heat. This action caused immediate destruction of tumor cells, while simultaneously initiating PFP phase transformation to release DOX, resulting in both photothermal and chemotherapeutic antitumor effects. Notably, the FA-DOX-ICG-PFP@Lip showed good biocompatibility and no systemic toxicity was observed after laser irradiation in RB tumor-bearing mice. Hence, the FA-DOX-ICG-PFP@Lip shows great promise for dual-modal imaging-guided chemo/photothermal therapy, and may have significant value for diagnosing and treating RB.

Application of contrast-enhanced ultrasound in minimally invasive ablation of benign thyroid nodules

Objective

This study aimed to investigate the application value of contrast-enhanced ultrasound (CEUS) before and after minimally invasive ablation procedures for benign thyroid nodule(s) (BTN).

Methods

This prospective study included patients with BTNs scheduled to undergo ultrasound-guided minimally invasive ablation treatment. CEUS was performed before and after ablation (at 1 day, and 1, 6, and 12 months after ablation). Changes in microvascular perfusion and the volume of BTNs were noted and assessed.

Results

Sixty-two patients (62 BTNs), who underwent ablation procedures between June 2016 and August 2020, were included. All lesions were confirmed by biopsy, and histopathological results were obtained before ablation treatment. On preoperative CEUS, the lesions exhibited hyperenhancement (53.23%) or iso-enhancement (46.77%) during the arterial phase, and all lesions exhibited iso-enhancement in the venous and late phases. One day after ablation, none of the BTNs exhibited obvious enhancement on CEUS. One (1.61%) lesion was re-treated due to a nodule-like enhancement area detected by CEUS at the 6-month follow-up. The mean nodular volume reduction rate (VRR) at 1, 6, and 12 months follow-up demonstrated no significant difference between the two ablation groups (microwave ablation versus radiofrequency ablation). Twelve months after ablation, the mean (±SD) VRR of all BTNs was 60.3 ​± ​10.3%.

Conclusion

CEUS helped guide treatment decisions for BTNs before ablation treatment. Moreover, it could also be used to accurately and noninvasively evaluate treatment efficacy.

Performance of Contrast-Enhanced Ultrasound in Thyroid Nodules: Review of Current State and Future Perspectives

Ultrasound has been established as a baseline imaging technique for thyroid nodules. The main advantage of adding CEUS is the ability to assess the sequence and intensity of vascular perfusion and hemodynamics in the thyroid nodule, thus providing real-time characterization of nodule features, considered a valuable new approach in the determination of benign vs. malignant nodules. Original studies, reviews and six meta-analyses were included in this article. A total of 624 studies were retrieved, and 107 were included in the study. As recognized for thyroid nodule malignancy risk stratification by US, for acceptable accuracy in malignancy a combination of several CEUS parameters should be applied: hypo-enhancement, heterogeneous, peripheral irregular enhancement in combination with internal enhancement patterns, and slow wash-in and wash-out curve lower than in normal thyroid tissue. In contrast, homogeneous, intense enhancement with smooth rim enhancement and "fast-in and slow-out" are indicative of the benignity of the thyroid nodule. Even though overlapping features require standardization, with further research, CEUS may achieve reliable performance in detecting or excluding thyroid cancer. It can also play an operative role in guiding ablation procedures of benign and malignant thyroid nodules and metastatic lymph nodes, and providing accurate follow-up imaging to assess treatment efficacy.

The Role of CEUS in the Evaluation of Thyroid Cancer: From Diagnosis to Local Staging

Ultrasound often represents the first diagnostic step for thyroid nodule evaluation in clinical practice, but baseline US alone is not always effective enough to achieve thyroid nodule characterization. In the last decades new ultrasound techniques, such as CEUS, have been introduced to evaluate thyroid parenchyma as recommended by EFSUMB guidelines, for use in clinical research field, although its role is not yet clear. Several papers show the potential utility of CEUS in the differential diagnosis of benign and malignant thyroid nodules and in the analysis of lymph node involvement in neoplastic pathology. Therefore, we carried out an evaluation of the literature concerning the role of CEUS in three specific areas: the characterization of the thyroid nodule, the evaluation of minimally invasive treatment and loco-regional staging of the lymph node in proven thyroid cancer. According to evidence reported, CEUS can also play an operative role in nodular thyroid pathology as it is able to guide ablation procedures on thyroid nodule and metastatic lymph nodes, to assess the radicality of surgery, to evaluate disease relapse at the level of the margins of ablated regions and to monitor the clinical evolution of necrotic areas in immediate post-treatment setting.

Value of Conventional Ultrasonography with Contrast-Enhanced Ultrasonography in the Differential Diagnosis of Partial Cystic Thyroid Nodules

The value of contrast-enhanced ultrasonography (CEUS) in the diagnosis of malignant partial cystic thyroid nodules (PCTNs) remains unclear. Thus, in the present study, the data of patients with pathologically proven PCTNs who underwent CEUS in the Chinese PLA General Hospital from January 2016 to February 2019 were retrospectively reviewed, and the imaging characteristics of benign and malignant PCTNs were compared. A total of 177 PCTNs were enrolled in this study, including 58 (32.7%) malignant nodules and 119 (67.2%) benign nodules. Six characteristics significantly differed between malignant PCTNs and benign PCTNs in univariate comparison: position of the solid portion (χ² = 17.937, p < 0.001), microcalcifications (χ² = 81.382, p < 0.001), boundaries (χ² = 45.486, p < 0.001), echogenicity (χ² = 11.152, p = 0.004), intensity of enhancement (χ² = 40.656, p < 0.001) and uniformity of enhancement (χ² = 19.933, p < 0.001). Among these, microcalcifications, boundaries, position of the solid portion, and uniformity of enhancement were independent risk factors in the multivariate comparison. A logistic regression model for predicting benign and malignant PCTNs was established with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 89.0% (95% confidence interval [CI]: 0.788-0.961), 91.0% (95% CI: 0.830-0.946), 81.0% (95% CI: 0.715-0.881), 95.0% (95% CI: 0.892-0.974) and 90.0% (95% CI: 0.844-0.938), respectively. The area under the receiver operating characteristic curve was 0.967 (95% CI: 0.944-0.990), which was significantly higher than that of conventional ultrasound only (0.747, 95% CI: 0.663-0.831, Z = 2.090, p = 0.0366). CEUS can be used in the diagnosis of PCTNs, and the four characteristics of malignant PCTNs proven by our study were microcalcifications, unclear boundaries, eccentric distributions of the solid parts and heterogeneous enhancement.

The value of superb microvascular imaging (SMI) scoring assignment method in differentiating benign and malignant thyroid nodules by conventional ultrasound

PURPOSE

To explore the application value of SMI scoring assignment method combined with 2017 American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS) in differentiating benign and malignant thyroid nodules.

METHODS

According to the 2017 ACR TI-RADS classification, the enrolled nodules were divided into 3 points group, 4 points group, 5 points group, 6 points group and≥7 points group. The nodules were assigned scores according to the echocity of the nodules and the microvessels detected by SMI and their distribution patterns based on ACR TI-RADS. Accompany with the scores increased or decreased after assignment, the thyroid nodules were re-grouped.

RESULTS

The AUC after the scores assignment is better than before (Z = 3.881, P <  0.001). The specificity, positive predictive value and accuracy after score assigned are better than those of before (Z = 8.323, P <  0.001; Z = 8.619, P <  0.001; Z = 5.345, P <  0.001), there is no statistical difference in sensitivity before and after score assigned (Z = -0.513, P = 0.60), and the negative predictive value before assigned score is better than that of after (Z = -3.826, P <  0.001).

CONCLUSION

The diagnostic efficacy after scoring was better than that of before.

High-performance sonographical multimodal imaging of non cystic thyroid lesions: Chances of the preoperative diagnostics in relation to histopathology

AIM:

To improve preoperative diagnostics of solid non-cystic thyroid lesions by using new high-performance ultrasound techniques: optimized B-mode morphology, elastography, Color-Coded Doppler-Sonography (CCDS) and contrast enhanced ultrasound (CEUS)

MATERIALS AND METHODS:

In 33 cases solid, non-cystic thyroid lesions were rated as TIRADS 3 and up from conventional B-mode examinations. Additional high resolution Power Doppler including HR- and Glazing-Flow as optimized macrovascularization techniques, shear wave elastography and CEUS were performed on these patients by one experienced examiner. For CEUS a bolus of 1–2.4 ml Sulfurhexafluorid microbubbles (SonoVue®, Bracco, Milan, Italy) was injected into a cubital vein and then the distribution kinetics of the contrast agent were documented from the early arterial phase (10 to 15 seconds after injection) to the late venous phase (5 minutes after injection). Postoperative histopathology was the diagnostic gold standard as it provides the most reliable proof.

RESULTS:

33 patients (13 males, 20 females; age 29 –77 years; mean 55 years; SD 13 years) were included in this study. 28 of them had benign regressive thyroid nodules, 3 had adenomas and 4 were diagnosed with carcinomas (3 were histologically identified as papillary thyroid carcinomas, one as a medullary thyroid carcinoma). The volume of the thyroid gland ranged from 6.6 to 401.3 cm² (mean 72.6±92.0 cm²).

The adenoma diameters ranged from 9 to 40 mm (mean 22±16 mm) and the carcinoma diameters ranged from 19 to 33 mm (mean 26±6 mm). The 3 adenomas had different echogenicities: One was completely echofree, one was hypoechoic and one isoechoic. The 4 carcinomas however were equally characterized as hypoechoic and echofree. Two of three adenomas and all of the carcinomas showed an incomplete or diffuse margin. Micro-calcifications were found in one adenoma and in every carcinoma. However, no micro-calcifications were observed in cases of benign regressive nodules.

Performing shear-wave elastography the adenomas showed lower values than the carcinomas: The tissue velocity of the adenomas ranged from 2.86 m/s to 3.85 m/s (mean 3.32±0.5 m/s) and in carcinomas from 3.89 m/s to 5.66 m/s (mean 4.18±0.3 m/s).

Marginal hypervascularization was detected in two adenomas after applying CCDS. One adenoma was hypovascularized. The four carcinomas showed an irregular extreme hypervascularization along their margins as well as an irregular central normo- or hypervascularization in CCDS. The additional HR-Flow helped reducing artefacts.

In CEUS the dynamic capillary microvascularization of all carcinomas was very irregular with early enhancement and followed by partial or complete wash-out. In CEUS two adenomas had no wash-out and the other one showed a partial wash-out.

CONCLUSION:

Using modern multimodal imaging offers new possibilities for the differentiation between benign and malignant thyroid lesions. It is a very important diagnostic tool in addition to the B-Mode TIRADS classification and eases the decision between TIRADS 3, 4 and 5. However, additional multicenter studies are required for more detailed evaluations.

Contrast-enhanced ultrasound (CEUS) and perfusion imaging using VueBox®

The external perfusion software (VueBox™) for contrast-enhanced ultrasound (CEUS), enables the quantitative analysis of micro-vascularization within non-cystic lesions in terms of characterization and detection. This review summarizes our work about parathyroid gland, thyroid gland, liver, prostate and other tissues as well as original studies in the use of parametric perfusion imaging. Useful perfusion parameters are introduced.

Contrast-Enhanced Ultrasound in the Differential Diagnosis and Risk Stratification of ACR TI-RADS Category 4 and 5 Thyroid Nodules With Non-Hypovascular

Objective

This study aims to investigate the value of contrast-enhanced ultrasound (CEUS) in the differential diagnosis and risk stratification of ACR TI-RADS category 4 and 5 thyroid nodules with non-hypovascular.

Methods

From January 2016 to December 2019 in our hospital, 217 ACR TI-RADS category 4 and 5 nodules with non-hypovascular in 210 consecutive patients were included for a derivation cohort. With surgery and/or fine-needle aspiration (FNA) as a reference, conventional ultrasound (US) features and CEUS features were analyzed. Multivariate logistic regression analysis was used to screen the independent risk factors and establish a risk predictive model. Between January 2020 and March 2021, a second cohort of 100 consecutive patients with 101 nodules were included for an external validation cohort. The model was converted into a simplified risk score and was validated in the validation cohort. The area under the receiver operating characteristic curves (AUC) were used to assess the models’ diagnostic performance.

Results

Micro-calcification, irregular margin, earlier wash-out, centripetal enhancement, and absence of ring enhancement were independent risk factors and strongly discriminated malignancy in the derivation cohort (AUC = 0.921, 95% CI 0.876–0.953) and the validation cohort (0.900, 0.824–0.951). There was no significant difference (P = 0.3282) between the conventional US and CEUS in differentiating malignant non-hypovascular thyroid nodules, but a combination of them (the predictive model) had better performance than the single method (all P <0.05), with a sensitivity of 87.0%, specificity of 86.2%, and accuracy of 86.6% in the derivation cohort. The risk score based on the independent risk factors divided non-hypovascular thyroid nodules into low-suspicious (0–3 points; malignancy risk <50%) and high-suspicious (4–7 points; malignancy risk ≥ 50%), the latter with nodule ≥10mm was recommended for FNA. The risk score showed a good ability of risk stratification in the validation cohort. Comparing ACR TI-RADS in screening suitable non-hypovascular nodules for FNA, the risk score could avoid 30.8% benign nodules for FNA.

Conclusions

CEUS is helpful in combination with conventional US in differentiating ACR TI-RADS category 4 and 5 nodules with non-hypovascular. The risk score in this study has the potential to improve the diagnosis and risk stratification of non-hypovascular thyroid nodules.

Utility of quantitative contrast-enhanced ultrasound for the prediction of lymph node metastasis in patients with papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to find the optimal parameters and cutoffs to differentiate metastatic lymph nodes (LNs) from benign LNs in the patients with papillary thyroid carcinoma (PTC) on the quantitative contrast-enhanced ultrasound (CEUS) features.

METHODS

A total of 134 LNs in 105 patients with PTCs were retrospectively enrolled. All LNs were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. The diagnostic efficacy of CEUS parameters was analyzed.

RESULTS

Univariate analysis indicated that metastatic LNs more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, ring-enhancing margins, higher PI, larger AUC, longer TTP and DT/2 than benign LNs at pre-operative CEUS (p <  0.001, for all). Multivariate analysis showed that centripetal or asynchronous perfusion (OR = 3.163; 95% CI, 1.721-5.812), hyper-enhancement(OR = 0.371; 95% CI, 0.150-0.917), DT/2 (OR = 7.408; 95% confidence interval CI, 1.496-36.673), and AUC (OR = 8.340; 95% CI, 2.677-25.984) were predictive for the presence of metastatic LNs. The sensitivity and accuracy of the quantitative CEUS were higher than qualitative CEUS (75% vs 55 % and 83.6% vs 76.1 % , respectively).

CONCLUSIONS

Quantitative CEUS parameters can provide more information to distinguish metastatic from benign LNs in PTC patients; In particular, DT/2 and AUC have a higher sensitivity and accuracy in predicting the presence of metastatic LNs and reduce unnecessary sampling of benign LNs.

Contrast-enhanced ultrasound for the differential diagnosis of thyroid nodules: An updated meta-analysis with comprehensive heterogeneity analysis

The diagnostic accuracy of contrast-enhanced ultrasound (CEUS) for distinguishing malignant thyroid nodules from benign thyroid nodules remains controversial. This meta-analysis was performed to evaluate the overall diagnostic value of CEUS for the characterization of thyroid nodules. Relevant studies were identified by searching PubMed, Embase and the Cochrane Library until August 1th 2019 to assess the overall diagnostic accuracy of CEUS. 37 eligible studies were included in the present meta-analysis. The pooled sensitivity, specificity, positive likelihood rate, negative likelihood rate and diagnostic odds ratio of CEUS were 0.87, 0.83, 5.38, 0.17 and 38.94, respectively, with the AUC of 0.9263. Subgroup analysis showed the heterogeneity was greatly reduced in small nodules group (≤ 1 cm) (I2 = 0.0%), while heterogeneity was still observed in the group of variable sizes group (I2 = 69.5%). However, meta-regression analysis revealed that only diagnostic criterion was the major source of heterogeneity (p = 0.0259). The risk of publication bias was negligible (p = 0.35). CEUS exhibited high accuracy for the identification of thyroid nodules and might provide additional perfusion information for the current US imaging reporting systems.

Combination of contrast-enhanced ultrasound and strain elastography to assess cytologically non-diagnostic thyroid nodules

The aim of the present study was to investigate the benefits of combining contrast-enhanced ultrasound (CEUS) and strain elastography (SE) for the diagnosis of thyroid nodules with non-diagnostic fine-needle aspiration cytology (FNAC) results. Between October 2013 and March 2017, CEUS and SE were performed in 226 patients (236 thyroid nodules) with non-diagnostic FNAC results prior to thyroidectomy. The diagnostic value of CEUS, SE and their combination (CEUS+SE) in distinguishing malignant from benign thyroid nodules was evaluated, using surgical pathology as a reference. Receiver operating characteristic curve analysis was used to assess the diagnostic performance of CEUS, SE and CEUS+SE in determining malignant thyroid nodules. Subsequently, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of CEUS, SE and CEUS + SE were calculated. The malignancy rate in patients with thyroid nodules and non-diagnostic FNAC results was 26.3% in the present study. The sensitivity, specificity, PPV, NPV, accuracy and area under the curve in predicting malignant thyroid nodules were 80.6, 85.6, 66.7, 92.5, 84.3 and 0.831%, respectively, using SE alone; 59.7, 95.9, 84.1, 86.9, 86.4 and 0.778%, respectively, using CEUS alone; and 83.9, 89.1, 73.6, 94.5, 88.1 and 0.865%, respectively, using the combination of CEUS and SE. Overall, the combination of CEUS with SE resulted in higher sensitivity, NPV and accuracy in the diagnosis of cytologically non-diagnostic thyroid nodules compared with CEUS or SE alone.

Folate-receptor-targeted laser-activable poly(lactide-co-glycolic acid) nanoparticles loaded with paclitaxel/indocyanine green for photoacoustic/ultrasound imaging and chemo/photothermal therapy

BACKGROUND

Cancer is one of the most serious threats to human health. Precision medicine is an innovative approach to treatment, as part of which theranostic nanomedicine has been studied extensively. However, the required biocompatibility and substantial cost for the approval of nanomedicines hinder their clinical translation.

PURPOSE

We designed a novel type of theranostic nanoparticle (NP) folate-receptor-targeted laser-activatable poly(lactide-co-glycolic acid) (PLGA) NPs loaded with paclitaxel (Ptx)/indo-cyanine green (ICG)-folic acid-polyethylene glycol (PEG)-PLGA-Ptx@ICG-perfluorohexane (Pfh)- using safe and approved materials and drugs, which would facilitate clinical translation. With laser irradiation, highly efficient photothermal therapy can be achieved. Additionally, targeted NPs can be activated by near-infrared laser irradiation at a specific region, which leads to the sharp release of Ptx at areas of high folate-receptor expression and ensures a higher Ptx concentration within the tumor region, thereby leading to chemo/photothermal synergistic antitumor efficacy. Meanwhile, the NPs can be used as a dual-modality contrast agent for photoacoustic and ultrasound imaging.

MATERIALS AND METHODS

FA-PEG-PLGA-Ptx@ICG-Pfh NPs were prepared by sonification method and characterized for physicochemical properties. Cytotoxicity and in vivo biocompatibility were evaluated respectively by CCK8 assay and blood analysis. NPs as dual-modality contrast agents were evaluated by photoacoustic/ultrasound imaging system in vitro and in vivo. In vitro anticancer effect and in vivo anticancer therapy was evaluated by CCK8 assay and MDA-MB231 tumor-bearing mice model.

RESULTS

FA-PEG-PLGA-Ptx@ICG-Pfh NPs were in the size of 308±5.82 nm with negative zeta potential and showed excellent photothermal effect. The NPs could be triggered sharp release of Ptx by laser irradiation, and showed the good biocompatibility in vitro and in vivo. Through photoacoustic/ultrasound imaging, the NPs showed an excellent ability as dual-modality contrast agents in vitro and in vivo. FA-PEG-PLGA-Ptx@ICG-Pfh NPs with laser irradiation showed the best anticancer efficacy in vitro and in vivo.

CONCLUSION

Such a biocompatible and novel theranostic NP is expected to integrate dual-modality imaging with improved therapeutic efficacy and provide a promising paradigm for cancer therapy.

Application of contrast-enhanced ultrasound for evaluation of thyroid nodules

Contrast-enhanced ultrasound (CEUS) is widely used to evaluate tumor microcirculation, which is useful in the differential diagnosis between benignity and malignancy. In the last 10 years, the applicability of CEUS to thyroid nodules has greatly improved due to technological refinements and the development of second-generation contrast agents. In this review, we summarize the applications of CEUS for thyroid nodules, focusing on the imaging findings of malignant and benign nodules in the existing literature and the use of those findings to predict malignancies, with an additional brief description of the utilization of CEUS for other thyroid-related diseases.

The Value of Peripheral Enhancement Pattern for Diagnosing Thyroid Cancer Using Contrast-Enhanced Ultrasound

BACKGROUND

Contrast-enhanced ultrasound (CEUS) scanning can detect differences between thyroid tumors and surrounding tissues. However, enhancement patterns within nodules are insufficient for the diagnosis of thyroid carcinomas. The peripheral enhancement patterns of nodules may provide useful diagnostic information. The objective of this study was to investigate the diagnostic accuracy of the peripheral enhancement patterns during CEUS scanning of thyroid nodules.

MATERIAL AND METHODS

120 nodules with peripheral rings during CEUS and definite pathology confirmed by surgery were included in this study. The internal and peripheral CEUS enhancement patterns of these nodules were assessed, and the diagnostic value of CEUS was compared with the conventional ultrasound. The relationship of types of peripheral rings and sizes of nodules was analyzed, respectively.

RESULTS

There were 78 benign and 42 malignant nodules. Peripheral irregular ring performs well in detecting malignancy. It improves the diagnostic performance of CEUS by combining with internal enhancement patterns (diagnostic sensitivity of 97.6%, specificity of 98.7%, and accuracy of 98.3%) and adds value to conventional ultrasound (95.2%, 70.5%, and 79.2%). The sizes of the nodules with regular high-enhanced rings (2.34 ± 1.33 cm) were larger than the other three types of peripheral rings (P < 0.05).

CONCLUSIONS

Features of peripheral ring on CEUS are important for the diagnosis of thyroid cancer; they can further contribute to the accuracy combining with the internal enhancement pattern, which could avoid the unnecessary biopsy.

Values of ultrasound features and MMP-9 of papillary thyroid carcinoma in predicting cervical lymph node metastases

Preoperative assessment of the cervical lymph node status is important in therapeutic schedule and further evaluations of prognosis for papillary thyroid carcinoma (PTC) patients. Our aim was to investigate the diagnostic values of conventional ultrasound (US), contrast-enhanced ultrasound (CEUS) features and the expression of MMP-9 of PTC in predicting the cervical lymph node metastases (LNM). In total, 156 patients with PTC confirmed by surgical pathology were included. Seventy-one patients had cervical LNM, while 85 patients had no LNM. The patients had cervical LNM (39.51 ± 13.29 years) were younger than those had no LNM (44.15 ± 10.94 years) (P = 0.02). Multivariate logistic regression results showed that tumor size ≥0.95 cm (OR = 13.47), ill-defined margin (OR = 4.31), internal heterogeneous low-enhancement (OR = 5.19) and ECE (OR = 25.25) were predictive for the presence of cervical LNM. The detection rate of ECE for the PTC with LNM by CEUS (81.48%, 44/54) was higher than by US (46.30%, 25/54). There was significant difference in MMP-9 intensity between PTC with and without cervical LNM (P = 0.000), and intense reactions (+++) were mainly found in the PTCs with LNM (80.95%, 17/21). In conclusion, the combination of conventional US, CEUS features and MMP-9 expression may serve as an effective tool for predicting the cervical LNM of PTC.

The diagnostic performances of conventional strain elastography (SE), acoustic radiation force impulse (ARFI) imaging and point shear-wave speed (pSWS) measurement for non-calcified thyroid nodules

BACKGROUND

Non-calcified thyroid nodules are relatively difficult to diagnose only relying on features of at conventional US images.

OBJECTIVE

To investigate the diagnostic performances of conventional strain elastography (SE), acoustic radiation force impulse (ARFI) SE and point shear-wave speed (pSWS) measurement for non-calcified thyroid nodules.

METHODS

A total of 201 non-calcified thyroid nodules in 195 patients were studied. They were examined with conventional ultrasound (US), conventional SE, ARFI SE and pSWS measurement. Their diagnostic performances and multivariable models were assessed with receiver operating characteristic (ROC) curve and logistic regression analyses respectively.

RESULTS

There were 156 benign and 45 malignant non-calcified nodules proven by histopathology or cystology. The mean diameters of the nodules were 21.2±10.8 mm. Areas under receiver operating characteristic curve (AUCs) of elastography features (ranged, 0.488-0.745) were all greater than that of US (ranged, 0.111-0.332). At multivariate analysis, there were three predictors of malignancy for non-calcified nodules, including pSWS of nodule (odds ratio [OR], 34.960; 95% CI, 11.582-105.529), marked hypoechogenicity (OR, 16.223; 95% CI, 1.761-149.454) and ARFI SE grade (OR, 10.900; 95% CI, 3.567-33.310). US+SE+pSWS owned the largest AUC (0.936; 95% CI, 0.887-0.985; P < 0.05), followed by US+pSWS (0.889; 95% CI, 0.823-0.955), and the poorest was US (0.727; 95% CI, 0.635-0.819).

CONCLUSIONS

ARFI SE and pSWS measurement had better diagnostic performances than conventional SE and US. When US combined with SE and pSWS measurement, it could achieve an excellent diagnostic performance and might contribute a better decision-making of FNA for non-calcified thyroid nodules.

Comparison of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Virtual Touch Tissue Quantification (VTQ) for diagnosis of thyroid nodules

OBJECTIVE

The aim of this study was to compare the diagnostic performance of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Virtual Touch Tissue Quantification (VTQ) in differentiating benign from malignant thyroid nodules (TNs).

MATERIALS AND METHODS

In this study 107 TNs in 107 patients were enrolled and analyzed. All of them were detected by conventional ultrasound (US) and confirmed by fine-needle aspiration (FNA) biopsy or surgery. VTIQ and VTQ examinations were performed on each nodule. Thereafter the median and mean of shear wave speed (SWS) values in lesions on VTIQ and VTQ were computed (SWS-median and SWS-mean). With cytological results of FNA and histological results adopted as the reference standard, area under the receiver operating characteristic (AUROC) curve analysis was performed to evaluate the diagnostic efficiency of VTIQ and VTQ in differentiation of TNs.

RESULTS

Among the 107 lesions, 19 were papillary thyroid carcinomas (PTCs), 1 was medullary thyroid carcinoma (MTC) and 87 were benign. In total lesions, AUROC-median in VTIQ was significantly higher than that in VTQ (0.851 vs.0.759; p < 0.05).

CONCLUSION

VTIQ and VTQ were equivalent in diagnosing TNs when using SWS-mean, whereas VTIQ showed better performance in comparison with VTQ when using SWS-median.

Analysis of arterial dynamic micro-vascularization with contrast-enhanced ultrasound (CEUS) in thyroid lesions using external perfusion software: First results

AIM

To determine different perfusion characteristics of histo-pathologically proven adenomas and carcinomas of the thyroid gland with CEUS and perfusion software.

MATERIAL AND METHODS

Retrospective perfusion analysis of 25 patients with carcinomas and 41 cases of adenomas of the thyroid gland (30 males, 36 females; aged 18 - 85 years, mean 56 years). All cases were histologically analyzed. Perfusion analysis was independently performed using external perfusion software (VueBox®). TTP, mTT, Peak and Rise time were calculated.

RESULTS

Lesions' sizes ranged from 0.2 to 10.2 cm in carcinomas (mean 2.18 cm), and from 0.6 to 5.0 cm in adenomas (mean 2.25 cm). In 20 out of 25 carcinomas that were evaluated with CEUS, a complete wash-out in the late venous phase was found. Adenomas showed wash-out at the border.Perfusion analysis in VueBox® revealed some parameters which tend to show differences between adenomas and carcinomas, however did not reach the level of significance.Median Peak in carcinomas was highest at the margins (2945 rU), and lowest in the surroundings (1110 rU). Mean Transit Time (mTT) values showed no differences between center, margin and surrounding.In adenomas healthy tissue showed higher mTT values compared to the center (24.6 vs. 20.7 sec). Median Peak was highest in the surrounding tissue and lowest in the margins (1999 vs. 1129 rU). No statistical differences could be found in the comparisons.

CONCLUSION

CEUS with perfusion analysis offers new possibilities for the dynamic evaluation of micro-vascularization in thyroid adenomas and carcinomas. Using VueBox® the perfusion analysis of the arterial phase provides new parameters that help determine a lesion's malignancy or benignity. However a final assessment regarding malignancy and benignity of thyroid lesions using only CEUS and perfusion analysis of the arterial phase is not yet possible.

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.

Diagnostic Accuracy of Contrast-Enhanced Ultrasound Enhancement Patterns for Thyroid Nodules

Background

The aim of this study was to investigate the accuracy of contrast-enhanced ultrasound (CEUS) enhancement patterns in the assessment of thyroid nodules.

Material/Methods

A total of 158 patients with suspected thyroid cancer underwent conventional ultrasound (US) and CEUS examinations. The contrast enhancement patterns of the lesions, including the peripheries of the lesions, were assessed by CEUS scans. The relationship between the size of the lesions and the degree of enhancement was also studied. US- and/or CEUS-guided biopsy was used to obtain specimens for histopathological diagnosis.

Results

The final data included 148 patients with 157 lesions. Seventy-five patients had 82 malignant lesions and 73 patients had 75 benign lesions. Peripheral ring enhancement was seen in 40 lesions. The differences of enhancement patterns and peripheral rings between benign and malignant nodules were significant (p=0.000, 0.000). The diagnostic sensitivity, specificity, and accuracy for malignant were 88%, 65.33%, and 88.32%, respectively, for CEUS, whereas they were 98.33%, 42.67%, and 71.97%, respectively, for TC by conventional US. The misdiagnosis rate by conventional US was 57.33% and 34.67% by CEUS (p=0.005). With regard to the size of lesions, a significant difference was found between low-enhancement, iso-enhancement, high-enhancement, iso-enhancement with no-enhancement area and no-enhancement (p=0.000).

Conclusions

In patients with suspicious US characteristics, CEUS had high specificity and contributed to establishing the diagnosis. Therefore, CEUS could avoid unnecessary biopsy.

Diagnostic value of contrast-enhanced ultrasound in solid thyroid nodules with and without enhancement

We aimed to investigate different enhancement patterns of solid thyroid nodules on contrast-enhanced ultrasound (CEUS) and then to evaluate the corresponding diagnostic performance in the differentiation of benign and malignant nodules with and without enhancement. 229 solid thyroid nodules in 196 patients who had undergone both conventional ultrasound and CEUS examinations were classified into enhancement and non-enhancement groups. Besides, different enhancement patterns in the enhancement group were characterised with five indicators including arrival time, mode of entrance, echo intensity, homogeneity, and washout time. Then aforementioned indicators were compared between benign and malignant nodules of different sizes (<10 mm and >10 mm), and diagnostic performance of significant enhancement indicators was calculated. As for the enhancement group, there were statistically significant differences of <10 mm subgroup among three CEUS indicators including arrival time, mode of entrance, and washout time between malignant and benign thyroid nodules (p < 0.05), while all CEUS indicators showed statistically significant differences in the total group and ≥10 mm subgroup (p < 0.05). All the five CEUS indicators displayed better diagnostic performance with specificity (92.86, 92.14, 95.71, 90.71, and 90.71 %, respectively) and diagnostic accuracy (80.79, 79.48, 74.67, 75.11, and 81.66 %, respectively), while the sensitivity and negative predictive value of non-enhancement were 95.51 and 95.83 %, respectively, with an accuracy of 77.29 %. CEUS is a very promising diagnostic technique that could improve the diagnostic accuracy of identifying benign thyroid lesions to spare a large number of patients an unnecessary invasive procedure.