Ultrasound elastography for thyroid nodules: recent advances

Shear wave elastography for thyroid nodule evaluation in patients with chronic autoimmune thyroiditis

PURPOSE

Shear wave elastography (SWE) is a valuable tool in discerning the malignancy risk of thyroid nodules. This study investigates whether 2D-SWE can reliably differentiate malignant thyroid nodules in patients with chronic autoimmune thyroiditis (CAT), despite the challenges posed by fibrosis, which can increase tissue stiffness and complicate diagnosis.

METHODS

This retrospective observational study evaluated 130 thyroid nodules (91 benign, 39 malignant) in patients with underlying CAT using conventional ultrasound (B-mode) and 2D-SWE with SuperSonic Mach30 equipment (Supersonic Imagine, Aix-en-Provence, France). Pathology reports served as the reference standard.

RESULTS

Out of the 130 nodules, 30% were malignant, and 70% were benign. 2D-SWE proved to be an excellent distinguisher between benign and malignant nodules. Malignant nodules had significantly higher elasticity indices compared to benign nodules (mean elasticity index: 47.2 kPa vs. 18.1 kPa, p < 0.0001; maximum elasticity index: 75 kPa vs. 26.2 kPa, p < 0.0001). The mean elasticity index was the most reliable elastographic parameter (AUC 0.907, sensitivity 87.2% [95% CI: 77.3-94.0%], specificity 84.6% [95% CI: 75.4-91.5%], and NPV 93.9% for a cut-off value of 30.5 kPa).

CONCLUSION

Our results confirm that 2D-SWE can accurately diagnose malignant thyroid nodules in cases with CAT (p < 0.0001), supporting its use as a complementary tool to conventional ultrasound.

Use of ultrasound elastography in differentiating benign from malignant thyroid nodules: a prospective study

Purpose

Elastography is a real-time non-invasive ultrasonography modality wherein the tissue stiffness is evaluated by calculating the degree of tissue distortion in response to an external force. This study was undertaken to assess the diagnostic value of elastography in differentiating benign from malignant thyroid nodules.

Methodology

In this prospective comparative study, a total of 52 thyroid nodules from 44 euthyroid patients undergoing fine needle aspiration cytology were assessed. Elastography was performed by a single experienced sonologist, wherein the nodules were graded as per elastography scoring (ES), and the strain ratio (SR) for each nodule was computed. Final histopathology findings of the patients undergoing surgery were compared to elastography findings, and measures of diagnostic accuracy to differentiate between benign and malignant nodules were determined for ES and SR.

Results

Thirty (68.2%) females and 14 (31.8%) males, with a mean age of 45.18 ± 11.23 years, were assessed. Fourteen (31.8%) patients underwent thyroidectomy, and histopathology was reported for 18 (34.6%) nodules. In all, nine (17.3%) nodules were malignant, and 43 (82.7%) nodules were considered benign. ES demonstrated a sensitivity of 88.9%, specificity of 88.3%, PPV of 61.5%, NPV of 97.4%, and accuracy of 88.5% to identify benign thyroid nodules. The mean SR for benign nodules was significantly lower as compared to malignant nodules (2.72 ± 0.62 vs. 4.52 ± 0.75, P < 0.0001). The optimal cut-point value for SR to differentiate benign and malignant thyroid nodules was determined to be 3.8, with the sensitivity, specificity, PPV, NPV, and accuracy being 88.9%, 95.4%, 80%, 94.6%, and 94.2%, respectively.

Conclusion

Ultrasound elastography (ES and SR) demonstrated good diagnostic efficacy to differentiate benign thyroid nodules from the malignant ones, and can be a good supplementary tool to gray-scale ultrasonography. It can also help in reducing the rates of unnecessary fine needle-aspiration biopsy.

Can ultrasound strain elastography (USE) improve management of suspicious thyroid nodules measuring <10 mm? A systematic review

INTRODUCTION

Current UK guidelines state that suspicious thyroid nodules <10 mm do not require FNA. These are often followed up with serial ultrasound scans. Ultrasound Strain Elastography (USE) could provide a more accurate alternative and preclude the need for follow-up. Can USE identify nodules at greater risk of malignancy and streamline patient management?

METHODS

Systematic review methodology used. Inclusion criteria are: - Population: patients with suspicious thyroid nodules <10 mm.- Intervention: USE.- Comparator: Ultrasound features of nodules.- Outcome measure: FNA or surgical removal of nodules. Searches performed on 6 commercial databases, along with grey literature anddissertation databases. The QUADAS-2 diagnostic study checklist used for quality assessment.

RESULTS

8 studies included and a narrative analysis performed due to heterogeneity of results. The mean USE sensitivity is 74.3%, mean specificity 80.5%. Mean overall ultrasound sensitivity is 80.4%, specificity 71.0%. Results suggest that USE is not superior to ultrasound for detecting malignancy. Some study limitations, particularly the heterogeneity of reporting the ultrasound features preclude meaningful conclusion from being drawn.

CONCLUSION

USE is more accurate at identifying benign nodules than ultrasound. Nodules appearing benign on USE could be excluded from serial ultrasound follow-up. No significant difference was found between USE and ultrasound at identifying malignant nodules.

IMPLICATIONS FOR PRACTICE

As FNA is not recommended for suspicious thyroid nodules <10 mm, these are often followed up with multiple scans and clinician reviews. This increases pressure on healthcare systems and uncertainty for the patient. This review shows that USE is more accurate at identifying benign nodules than ultrasound alone, meaning that these nodules could potentially be excluded from serial follow up. This would streamline patient management, freeing-up vital resources in ENT and ultrasound departments.

Multi-Omics and Management of Follicular Carcinoma of the Thyroid

Follicular thyroid carcinoma (FTC) is the second most common cancer of the thyroid gland, accounting for up to 20% of all primary malignant tumors in iodine-replete areas. The diagnostic work-up, staging, risk stratification, management, and follow-up strategies in patients who have FTC are modeled after those of papillary thyroid carcinoma (PTC), even though FTC is more aggressive. FTC has a greater propensity for haematogenous metastasis than PTC. Furthermore, FTC is a phenotypically and genotypically heterogeneous disease. The diagnosis and identification of markers of an aggressive FTC depend on the expertise and thoroughness of pathologists during histopathological analysis. An untreated or metastatic FTC is likely to de-differentiate and become poorly differentiated or undifferentiated and resistant to standard treatment. While thyroid lobectomy is adequate for the treatment of selected patients who have low-risk FTC, it is not advisable for patients whose tumor is larger than 4 cm in diameter or has extensive extra-thyroidal extension. Lobectomy is also not adequate for tumors that have aggressive mutations. Although the prognosis for over 80% of PTC and FTC is good, nearly 20% of the tumors behave aggressively. The introduction of radiomics, pathomics, genomics, transcriptomics, metabolomics, and liquid biopsy have led to improvements in the understanding of tumorigenesis, progression, treatment response, and prognostication of thyroid cancer. The article reviews the challenges that are encountered during the diagnostic work-up, staging, risk stratification, management, and follow-up of patients who have FTC. How the application of multi-omics can strengthen decision-making during the management of follicular carcinoma is also discussed.

Strain Versus 2D Shear-Wave Elastography Parameters—Which Score Better in Predicting Thyroid Cancer?

The aim of this study is to assess the diagnostic performance of strain elastography (SE) versus 2D shear-wave elastography (2D-SWE) by providing a head-to-head comparison of the two methods. Ninety-four thyroid nodules were evaluated using conventional ultrasound (B-mode) and SE, namely, real-time elastography (RTE) with a Hitachi Preirus machine (Hitachi Inc., Tokyo, Japan) and consecutively, 2D-SWE with SuperSonic Mach30 equipment (Supersonic Imagine, Aix-en-Provence, France). The results were compared in all cases to the pathology reports. Out of the 94 nodules, 29 (30.9%) were malignant. Both SE and 2D-SWE parameters proved to have excellent diagnostic quality, with comparable results. The mean elasticity index was the best parameter for the 2D-SWE (AUC 0.912); for a cut-off value of 30.5 kPa, it predicts thyroid malignancy with a sensitivity of 79.3%, specificity of 95.38%, NPV of 91.2% and PPV of 88.5%. The best parameter for SE was the strain ratio (cutoff > 3.9; sensitivity 82.7%; specificity 92.3%; AUC 0.905). When integrated in the ultrasound risk algorithm, both elastography methods improved the diagnostic performance: AUC 0.764 vs. 0.886 vs. 0.861 for B-modes: B-mode + 2D-SWE vs. B-mode + SE. We concluded that elastography adds diagnostic value in predicting malignancy, both when Hitachi RTE and SuperSonic 2D-SWE were used.

Diagnostic Accuracy of Strain Ultrasound Elastography in Thyroid Lesions Compared to Fine-Needle Aspiration Cytology

Introduction

Strain ultrasound-guided elastography (USE) could be used to differentiate malignant from benign thyroid lesions if its sensitivity and specificity are significantly high. Data on whether to rely on USE in differentiating thyroid nodules are unavailable, and fine-needle aspiration cytology (FNAC) remains the gold standard. However, FNAC carries a significant financial burden on hospitals and psychological stress on patients. Therefore, we conducted this study to determine the diagnostic accuracy of strain USE in thyroid lesions.

Methodology

We conducted a descriptive cross-sectional study at the Radiology Department, Benazir Bhutto Hospital, Rawalpindi, from December 6, 2020, to June 5, 2021. The study included adult patients aged between 20 to 70 years who were referred with thyroid nodules or lesions found clinically or on routine neck ultrasound. The study excluded patients who had previous history of surgery or previously diagnosed with malignant thyroid lesions and recurrent thyroid nodules. Strain USE was performed on thyroid nodules, and the degree of strain was color-coded on a scale from red (soft, greatest elasticity) to green (intermediate, average strain) to blue (hard, no elasticity/strain). Lesions were given an elasticity score on a five-point scale. The lesion was given a score of one if the entire lesion was uniformly shaded in green. A lesion with mosaic pattern of green and blue was scored as two. A score of three denoted a lesion with green periphery and blue center on strain elastography. A score of four indicated uniform blue in the entire lesion, with green in the lesion's periphery. The highest score of five was given if the lesion and its surroundings demonstrated blue color. Ultrasound-guided FNAC of the thyroid nodules was performed following USE. Data was analyzed using IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp. Mean ± standard deviation for calculating quantitative variables. Frequencies and percentages were calculated for qualitative variables. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of strain USE was calculated taking FNAC as gold standard. We also conducted a receiver operating characteristic curve analysis to quantify the diagnostic accuracy of strain USE in thyroid lesions.

Results

The study included 207 adult patients (117 women, 56.52%; 90 men, 43.48%). The study population's mean age was 50.0 ± 11.8 years (range, 20 to 70 years). Most patients (56.52%) were aged 46 to 70 years. FNAC confirmed malignant thyroid nodules in 100 cases (true positive), and nine cases (false positive) had no malignant lesions on FNAC. In USE-negative patients, 91 were true negative, while seven were false negative. Strain USE's overall sensitivity was 93.46%, specificity was 91.0%, PPV was 91.74%, NPV was 92.86%, and diagnostic accuracy was 92.27% compared to the gold standard FNAC.

Conclusions

Strain USE in thyroid lesions is a noninvasive modality of choice with high diagnostic accuracy and has dramatically improved our ability to diagnose malignant thyroid nodules preoperatively. Strain USE also helps the surgeons in proper decision-making. Strain USE should be used routinely in all patients with thyroid lesions to help diagnose malignant thyroid nodules preoperatively and inform proper surgical and treatment plans.

Non-Toxic Multinodular Goiter: From Etiopathogenesis to Treatment

Goiter term is generally used for defining the enlargement of thyroid gland. Thyroid nodules are very common and some of these nodules may harbor malignancy. Multinodular goiter (MNG) disease without thyroid dysfunction is defined as non-toxic MNG. There are many factors in etiology for development of MNG. They can be classified as iodine dependent and non-iodine dependent factors basically. Beyond this basic classification, the effect of many environmental and acquired factors is also effective on the development of goiter. Many methods have described for diagnosis and treatment for non-toxic MNG. Biochemical tests, imagining methods, invasive and non-invasive methods have been used for diagnosis for many years. Each method has advantages and disadvantages, separately. Although the best method for diagnosis is still debatable, distinguishing malignant nodules from benign nodules is the first and most important step for MNG. Biochemical tests such as serum thyroid stimulating hormone (TSH) measurement, thyroid hormone measurement; and thyroid ultrasonography are used for diagnosis of MNG, traditionally. Nowadays, there are some new techniques were developed like ultrasound-elastography. Furthermore, thyroid scintigraphy may be used if there is abnormal TSH measurement. Fine-needle aspiration biopsy and some cross-sectional imaging methods (computed tomography, magnetic resonance imaging, and positron emission tomography) could be used, too. After a certain diagnosis is made, treatment options should be evaluated. Many treatment methods have been used for goiter from ancient times upon today. From non-invasive methods such as medical follow-up to invasive methods such as lobectomy or thyroidectomy are options for treatment. Patients with compression symptoms due to an enlarged thyroid gland are usually candidates for surgery. In this study, it is aimed to determine the most appropriate treatment for the patient by discussing the advantages and disadvantages of all these methods. The present review discusses definition of goiter term, etiology, epidemiology, pathogenesis, diagnostic methods, and treatment methods for nontoxic MNG.

Shear Wave Elastography and Thyroid Imaging Reporting and Data System (TIRADS) for the Risk Stratification of Thyroid Nodules-Results of a Prospective Study

Purpose: To compare the diagnostic performance of thyroid imaging reporting and data system (TIRADS) in combination with shear wave elastography (SWE) for the assessment of thyroid nodules. Methods: A prospective study was conducted with the following inclusion criteria: preoperative B-mode ultrasound (US) including TIRADS classification (Kwak-TIRADS, EU-TIRADS), quantitative SWE and available histological results. Results: Out of 43 patients, 61 thyroid nodules were detected; 10 nodules were found to be thyroid cancer (7 PTC, 1 FTC, 2 HüCC) and 51 were benign. According to Kwak-TIRADS the majority of benign nodules (47 out of 51, 92.2%) were classified in the low-risk- and intermediate-risk class, four nodules were classified as high-risk (7.8%). When using EU-TIRADS, the benign nodules were distributed almost equally across all risk classes, 21 (41.2%) nodules were classified in the low-risk class, 16 (31.4%) in the intermediate-risk class and 14 (27.4%) in the high-risk class. In contrast, most of the malignant nodules (eight out of ten) were classified as high-risk on EU-TIRADS. One carcinoma was classified as low-risk and one as intermediate-risk nodule. For SWE, ROC analysis showed an optimal cutoff of 18.5 kPa to distinguish malignant and benign nodules (sensitivity 80.0%, specificity 49.0%, PPV 23.5% and NPV 92.6%). The addition of elastography resulted in an increase of accuracy from 65.6% to 82.0% when using Kwak-TIRADS and from 49.2% to 72.1% when using EU-TIRADS. Conclusion: Our data demonstrate that the combination of TIRADS and SWE seems to be superior for the risk stratification of thyroid nodules than each method by itself. However, verification of these results in a larger patient population is mandatory.

Conventional ultrasound, color Doppler, TI-RADS, and shear wave elastography for thyroid nodule differentiation: a study of efficacy compared with the histopathology results

Background

Although a minority of the thyroid nodules is malignant, usually the invasive diagnostic procedures are warranted. This prospective study aims to assess the diagnostic performance of the US criteria in addition to the TI-RADS score and the SWE for the differentiation between the benign and malignant thyroid nodules as a potential surrogate for the invasive procedures.

Results

Ninety-nine patients with thyroid nodules (79 females and 20 males, with a mean age of 45.9 ± 7.7 years; 30–69 years) were enrolled in this study and underwent conventional ultrasound, color Doppler, TI-RADS scoring, and shear wave elastography (SWE); the findings were correlated to the histopathological results.

Our results revealed a significant increase in SWE elasticity indices (EIs) and presence of color Doppler signals in malignant nodules as compared with the benign ones (ρ < 0.05). Combined TI-RADS and SWE as well as TI-RADS and color Doppler imaging had given a better sensitivity for detection of malignancy.

Conclusion

Elasticity indices had shown a significantly high diagnostic performance that is almost approaching the histopathological results. Combined SWE, color Doppler and TI-RADS, as a sum of findings, could effectively differentiate between benign and malignant thyroid nodules. Furthermore, it had offered a non-invasive tool for accurate risk stratification of malignant nodules.

The impact of TI-RADS in detecting thyroid malignancies: a prospective study

INTRODUCTION

Thyroid ultrasonography (US) is the first-step noninvasive and easily accessible diagnostic method widely used in the detection and characterization of nodular thyroid disease. We aimed to develop a TI-RADS, which is easy to apply and only relies on the counting of suspicious criteria. In order to measure the reliability of the system, we investigated its correlation with fine needle aspiration biopsy (FNAB) and post-surgery histological results.

MATERIALS AND METHODS

In this prospective study, 242 patients who had undergone FNAB with simultaneous cytopathologist in the radiology department between April and August 2016 were analyzed. Before FNAB, the thyroid gland was re-evaluated with US, and TI-RADS classification was made. Demographic characteristics, family thyroid cancer history and radiotherapy history to the neck region were noted.

RESULTS

Of the 242 patients, 17.3% were male (42 males/200 females). US-guided FNAB was applied to all patients. Mean age was 50 ± 13 years (min: 19, max: 82). Both FNAB and final post-surgery histology results showed that sex and age were not statistically significantly associated with malignancy (p = 0.193) TI-RADS criteria and FNAB results revealed a statistically significant association between irregular contours, the state of anteroposterior diameter being longer than transverse diameter, microcalcifications, marked hypoechogenicity, and malignancy (p < 0,05). Thirty patients were TI-RADS ≥ 4, 206 patients were TI-RADS ≤ 3 and there was a significant correlation between TI-RADS and Bethesda classification (p = 0.001). In addition, statistically significant associations were found between malignancy and family history of thyroid cancer (p = 0.035) and radiotherapy history to the neck region (p = 0.01).

CONCLUSION

TI-RADS system after nodule identification is based only on the counting of suspicious criteria. It will be safe and effective to recommend follow-up with low score TI-RADS, benign characters and insufficient FNAB results, and thus, unnecessary thyroidectomy operations will be prevented. It will be easier for surgeons to recommend surgery and persuade the patients for it when patients have high TI-RADS scores. TI-RADS has high power in detecting malignancy by recommending biopsy of suspicious nodules.

Predictor Analysis in Radiofrequency Ablation of Benign Thyroid Nodules: A Single Center Experience

Purpose

To confirm the efficacy of ultrasound (US) guided radiofrequency ablation (RFA) in the treatment of benign thyroid nodules, we evaluated as primary outcome the technical efficacy and clinical success in a single center dataset. The secondary outcome was to find a correlation between nodules' pre-treatment features and volume reduction rate (VRR) ≥75% at 12 months after RFA and during follow-up period.

Methods

This retrospective study included 119 consecutive patients (99 females, 20 males, 51.5 ± 14.4 years) with benign thyroid nodules treated in our hospital between October 2014 and December 2018 with a mean follow-up of 26.8 months (range 3-48). Clinical and US features before and after RFA were evaluated by a US examination at 1, 3, 6, 12 months and annually thereafter up to 48 months.

Results

The median pre-treatment volume was 22.4 ml; after RFA we observed a statistically significant volume reduction from the first month (11.7 ml) to the last follow-up (p < 0.001 for all follow-up times). The median VRR was 47.1, 55.3, 61.2, 67.6, 72.8, 71.3, and 62.9% at 1, 3, 6, 12, 24, 36, and 48 months of follow-up respectively, showing a progressive significant improvement up to 24 months (VRRs 1 vs 3 months, 3 vs 6 months and 6 vs 12 months p < 0.001, 12 vs 24 months p = 0.05) while no differences at 24 vs 36 and 36 vs 48 months were observed. Symptoms improved significantly (complete resolution 64.35%, partial resolution 35.65%), and neck circumference was reduced as compared to pre-treatment (p < 0.001). Lower pre-treatment neck circumference (37.5 vs 36.0 cm, p = 0.01) was a positive predictor of VRR ≥75% at 12 months. Macrocystic echostructure (HR 2.48, p 0.046) and pre-treatment volume >22.4 ml (HR 0.54, p 0.036) were found to be independent positive and negative predictors of VRR ≥75% respectively. One-month post RFA VRR ≥50% represented the best positive predictor of technical success.

Conclusions

This study confirmed the efficacy of RFA in the treatment of benign thyroid nodules. In particular we show that by selecting macrocystic nodules smaller than 22.4 ml better long-term response can be achieved, which is predicted by an early shrinkage of the nodule.

Retrospective analysis of the ultrasound features of resected thyroid nodules

PURPOSE

Several ultrasound (US) risk stratification systems (US-RSSs) have been proposed to stratify the risk of malignancy (ROM) of thyroid nodules. This risk might be overestimated due to selection bias and comparison with the cytological report alone. Our study aimed to compare ROM and diagnostic performance of three guidelines (ATA, AACE/ACE/AME, EUTIRADS) and evaluate the changes in unnecessary biopsy according to the nodule size cutoff for biopsy, using histology as gold standard.

METHODS

This retrospective observational study included 146 consecutive patients who underwent surgery after US and cytological characterization. We analyzed the effectiveness and accuracy of three US-RSSs.

RESULTS

46.6% of nodules were diagnosed as malignant. Applying US-RSS, the percentage of nodules that should have been analyzed by biopsy was 84.25% with ATA, 69.86% with EUTIRADS and 64.38% with AACE/ACE/AME systems. The ROM was 94.9%, 86.0%, 87.0% for high-risk category, 36.4%, 32.0%, 35.4% for intermediate-risk category and 22.9%, 0.0%, 22.9% for low-risk category by ATA, AACE/ACE/AME and EUTIRADS systems, respectively. EUTIRADS and AACE/ACE/AME systems were more accurate in differentiating malignant from benign cases. ATA score was the more sensitive US-RSS to identify malignant tumors within the high-risk category. About the unnecessary biopsies, in the intermediate-risk category, the application of the size criterion helps to increase specificity in all systems.

CONCLUSIONS

The US categorization of low and high-risk thyroid nodules using current US-RSSs helps alone to determine the optimal treatment option. Nodule size remains relevant to recommend biopsy for the intermediate-risk category.

Application of Shear Wave Elastography to Evaluate the Stiffness of Normal Testes and Inflammatory Epididymal Tail Masses

OBJECTIVE

This study aimed to investigate the application value of shear wave elastography in examining normal testes and inflammatory epididymal tail masses.

METHODS

We examined 110 healthy male volunteers (with a total of 220 testes) and 25 patients with epididymitis via conventional scrotal ultrasonography and shear wave elastography. The mean (Emean), minimal (Emin), maximal (Emax), and standard deviation (ESD) values of elasticity were acquired. The inflammatory masses were assessed at initial diagnosis, at weeks 1 and 2 of standard anti-inflammatory treatment, upon remission, and at 2 weeks after remission.

RESULTS

The Emean values of different regions in testes varied in the following order: center region (3.14 ± 0.35 kPa) < upper- or lower-pole capsule (upper, 3.94 ± 0.90 kPa; lower, 3.94 ± 0.97 kPa) < posterior capsule (5.96 ± 1.46 kPa) < anterior capsule (6.27 ± 1.58 kPa). The Emean value of the center of the testicular parenchyma in the short axis was significantly larger than that in the long axis (3.47 ± 0.32 vs 3.14 ± 0.35 kPa; P < 0.05). There were significant differences in the Emean value between inflammatory epididymal tail masses at initial diagnosis, at 1 and 2 weeks after treatment, upon remission, and at 2 weeks after remission (P < 0.05).

CONCLUSIONS

Shear wave elastography can be used to reflect the relative hardness of normal testes and inflammatory epididymal tail masses.

Diagnostic performance of combination of ultrasound elastography and BRAF gene detection in malignant thyroid nodule: a retrospective study

OBJECTIVES

The aims of our study were to explore the preoperative diagnostic value of ultrasound elastography combined with BRAF gene detection in malignant thyroid nodule, and find whether shear wave elastography (SWE) combined with BRAF gene detection can improve the diagnostic sensitivity and specificity.

METHODS

From 1480 patients with thyroid nodule examined between January 2015 and December 2017, a retrospective analysis was performed on 161 patients who underwent thyroidectomy. Diagnosis was confirmed by postoperative pathology, including 139 malignant thyroid nodules and 22 benign thyroid nodules. All the patients underwent SWE, BRAF gene detection, and the combination for their preoperative evaluation. The sensitivities, specificities, and accuracies of SWE, BRAF gene detection, and the combination for detection of malignant thyroid nodules were calculated and then compared using Fisher's exact probability test, based on the original preoperative reports and postoperative pathology. A receiver-operating characteristic curve analysis was performed to compare the diagnostic performance of SWE, BRAF gene detection, and combination for detecting malignant thyroid nodules.

RESULTS

Based on the original preoperative reports and postoperative pathology, SWE, BRAF gene detection, and the combination showed sensitivities of 88.67%, 78.41%, 92.8%, and specificities of 72.77%, 77.27%, 95.45%. A correct diagnosis was obtained in 85.82%, 78.26%, 93.16% and missed diagnosis rates were 12.23%, 21.58%, and 7.19%. The sensitivities, specificities, and correct diagnosis rate in the combination group were significantly higher than any single detection method (P<0.05). The missed diagnosis rate in the combination group was significantly lower than any single detection method (P<0.05). The receptor operating characteristics curve analysis showed a significantly higher diagnostic performance for the combination than for SWE and BRAF gene detection (P<0.05). The interobserver agreement for detecting malignant thyroid nodule was better for the combination than for SWE or BRAF gene detection alone.

CONCLUSION

For the detection of a malignant thyroid nodule, SWE combined with BRAF gene detection was more sensitive and showed a higher diagnostic performance than SWE or BRAF gene detection alone.

Current Ultrasound Technologies and Instrumentation in the Assessment and Monitoring of COVID-19 Positive Patients

Since the emergence of the COVID-19 pandemic in December of 2019, clinicians and scientists all over the world have faced overwhelming new challenges that not only threaten their own communities and countries but also the world at large. These challenges have been enormous and debilitating, as the infrastructure of many countries, including developing ones, had little or no resources to deal with the crisis. Even in developed countries, such as Italy, health systems have been so inundated by cases that health care facilities became oversaturated and could not accommodate the unexpected influx of patients to be tested. Initially, resources were focused on testing to identify those who were infected. When it became clear that the virus mainly attacks the lungs by causing parenchymal changes in the form of multifocal pneumonia of different levels of severity, imaging became paramount in the assessment of disease severity, progression, and even response to treatment. As a result, there was a need to establish protocols for imaging of the lungs in these patients. In North America, the focus was on chest X-ray and computed tomography (CT) as these are widely available and accessible at most health facilities. However, in Europe and China, this was not the case, and a cost-effective and relatively fast imaging modality was needed to scan a large number of sick patients promptly. Hence, ultrasound (US) found its way into the hands of Chinese and European physicians and has since become an important imaging modality in those locations. US is a highly versatile, portable, and inexpensive imaging modality that has application across a broad spectrum of conditions and, in this way, is ideally suited to assess the lungs of COVID-19 patients in the intensive care unit (ICU). This bedside test can be done with little to no movement of the patients from the unit that keeps them in their isolated rooms, thereby limiting further exposure to other health personnel. This article presents a basic introduction to COVID-19 and the use of the US for lung imaging. It further provides a high-level overview of the existing US technologies that are driving development in current and potential future US imaging systems for lung, with a specific emphasis on portable and 3-D systems.

Shear-wave elastography of the testicle: potential role of the stiffness value in various common testicular diseases

AIM

To assess the value and efficacy of real-time shear-wave elastography (SWE) of normal testicular parenchyma and various common testicular diseases in clinical practice.

MATERIALS AND METHODS

SWE was undertaken in 338 patients (mean age: 43.2±17.2 years, range 17-78 years) comprising normal testicles (n = 358), testicular microlithiasis (n = 40), and various testicular diseases (n = 208) and the stiffness was recorded. The final diagnosis was correlated with the clinical context, long-term follow-up, or histopathology. Statistical evaluation was performed to provide a stiffness threshold for pathological diagnosis.

RESULTS

The mean size of testicular lesions was 2.6±1.5 cm (range: 10-42 mm). The mean Young's modulus value for normal testis was recorded at 4.55±2.54 kPa. Whatever the stage of microlithiasis, a higher statistically significant stiffness value was recorded. For acute orchitis, the mean stiffness value was slightly higher, but not statistically significantly. The testicular tumoural processes presented a median stiffness value of 21.02 kPa with a cut-off of 16.1 kPa. Fibrosis presented the highest median stiffness value of 30.03 kPa with a cut-off of 26.3 kPa. By analysing the distribution of the different pathological groups, the difference was statistically significant between fibrosis and tumoural processes (p = 0.001).

CONCLUSION

SWE is a feasible technique in the exploration of the testicular parenchyma. SWE values can be used to differentiate testicular fibrosis from a tumoural process with confidence.

A pragmatic assessment of the British Thyroid Association "U classification" of thyroid nodules with a focus on their follow-up

AIM

To assess the predictive value of the U classification and the significance of follow-up ultrasound in those managed conservatively.

MATERIALS AND METHODS

A retrospective observational study was carried out among 1,465 patients who underwent thyroid ultrasound in 2016 at a teaching hospital in UK. Details regarding U classification of nodules, cytology, histology in patients who underwent surgery, and follow-up ultrasound in those managed conservatively were obtained.

RESULTS

Thyroid surgery was performed in 129 patients of which malignancy was seen in 35 (27.1%). The proportion of patients with cancer in U1-U5 categories were 0%, 13.6%, 30.4%, 40%, and 100%, respectively (Fisher's exact test p=0.001). There was no significant difference in U stage, cytology, or histology between incidental and symptomatic nodules. Among patients who did not undergo surgery 5% of U1, 14.6% of U2, 75% of U3, and 71.4% of U4 underwent repeat ultrasound. Radiological progression in nodule size was seen in 4.2% of U1, 1.9% of U2, 0% of U3, and 40% of U4 nodules at median duration of 306, 439, 274, and 748 days, respectively.

CONCLUSIONS

U classification is reliable in risk-stratifying thyroid nodules. Patients with benign nodules without high-risk features do not require follow-up. The interval between scans in patients with indeterminate nodules can be extended to a period of 6-12 months.

Elastography for the evaluation of thyroid nodules in pediatric patients

Objective

To evaluate the usefulness of elastography (using manual compression) as an additional diagnostic tool for children and adolescents with thyroid nodules.

Materials and Methods

This was a prospective study conducted between September 2012 and August 2013 at a hospital in Brazil. We performed elastography, ultrasound, and fine-needle aspiration biopsy in 32 patients between 6 and 18 years of age who had, in total, 38 thyroid nodules.

Results

The elastography findings correlated with the histopathological diagnosis in 78.5% of cases. In three patients, an unnecessary thyroidectomy could have been avoided if the elastography results had been prioritized. Only one malignant thyroid nodule was found to show high elasticity.

Conclusion

Our results suggest that high elasticity of a nodule on elastography is associated with a low risk of thyroid cancer. If further confirmed in other studies, elastography may prove useful as a complementary test for screening thyroid nodules in children.

Machine Learning-Assisted System for Thyroid Nodule Diagnosis

Background: Ultrasound (US) examination is helpful in the differential diagnosis of thyroid nodules (malignant vs. benign), but its accuracy relies heavily on examiner experience. Therefore, the aim of this study was to develop a less subjective diagnostic model aided by machine learning. Methods: A total of 2064 thyroid nodules (2032 patients, 695 male; M_age = 45.25 ± 13.49 years) met all of the following inclusion criteria: (i) hemi- or total thyroidectomy, (ii) maximum nodule diameter 2.5 cm, (iii) examination by conventional US and real-time elastography within one month before surgery, and (iv) no previous thyroid surgery or percutaneous thermotherapy. Models were developed using 60% of randomly selected samples based on nine commonly used algorithms, and validated using the remaining 40% of cases. All models function with a validation data set that has a pretest probability of malignancy of 10%. The models were refined with machine learning that consisted of 1000 repetitions of derivatization and validation, and compared to diagnosis by an experienced radiologist. Sensitivity, specificity, accuracy, and area under the curve (AUC) were calculated. Results: A random forest algorithm led to the best diagnostic model, which performed better than radiologist diagnosis based on conventional US only (AUC = 0.924 [confidence interval (CI) 0.895-0.953] vs. 0.834 [CI 0.815-0.853]) and based on both conventional US and real-time elastography (AUC = 0.938 [CI 0.914-0.961] vs. 0.843 [CI 0.829-0.857]). Conclusions: Machine-learning algorithms based on US examinations, particularly the random forest classifier, may diagnose malignant thyroid nodules better than radiologists.

Strain wave elastography in response assessment to neo-adjuvant chemotherapy in patients with locally advanced breast cancer

OBJECTIVE

The study was conducted to study the role of strain wave elastography in evaluating the response to neo-adjuvant chemotherapy (NACT) in patients with locally advanced breast cancer (LABC).

METHODS

In this Institutional review board approved study, 86 patients of LABC were investigated with strain wave elastography. Females receiving NACT had the affected breast scanned by strain wave elastography before each cycle of chemotherapy and immediately before surgery by two independent observers. Changes in elastographic parameters (size ratio, strain ratio) were documented and then compared to clinical and pathologic tumor response as evaluated after mastectomy.

RESULTS

Elastographic strain ratio parameters demonstrated high sensitivity and moderate specificity for determining response even after the first cycle of neo-adjuvant chemotherapy [97.7% sensitivity (Sn), 68.7% specificity (Sp)]. Elastographic size ratio parameters showed moderate sensitivity and specificity for response detection after second and third cycle of neo-adjuvant chemotherapy (Sn, Sp: after second cycle of NACT Sn 83.3% Sp 80%; after third cycle of NACT Sn 77.8% Sp 100%).

CONCLUSION

Strain ratio is the earliest predictor of treatment response in patients of LABC. Serial imaging with elastography has the potential to predict treatment response early during the course of NACT, which may prove vital in management of patients with breast cancer.

ADVANCES IN KNOWLEDGE

Strain wave elastography is a powerful tool to predict chemoresponse early during the course of management, thereby providing an optimal window to change treatment protocols.

Ultrasound elastography of the thyroid: principles and current status

Ultrasound (US) elastography has been introduced as a non-invasive technique for evaluating thyroid diseases. This paper presents a detailed description of the technical principles, peculiarities, and limitations of US elastography techniques, including strain elastography and shear-wave elastography. This review was conducted from a clinical perspective, and aimed to assess the usefulness of US elastography for thyroid diseases in specific clinical scenarios. Although its main focus is on thyroid nodules, the applications of US elastography for other thyroid diseases, such as diffuse thyroid diseases and thyroiditis, are also presented. Furthermore, unresolved questions and directions for future research are also discussed.

Nodular Thyroid Disease in the Era of Precision Medicine

Management of thyroid nodules in the era of precision medicine is continuously changing. Neck ultrasound plays a pivotal role in the diagnosis and several ultrasound stratification systems have been proposed in order to predict malignancy and help clinicians in therapeutic and follow-up decision. Ultrasound elastosonography is another powerful diagnostic technique and can be an added value to stratify the risk of malignancy of thyroid nodules. Moreover, the development of new techniques in the era of "Deep Learning," has led to a creation of machine-learning algorithms based on ultrasound examinations that showed similar accuracy to that obtained by expert radiologists. Despite new technologies in thyroid imaging, diagnostic surgery in 50-70% of patients with indeterminate cytology is still performed. Molecular tests can increase accuracy in diagnosis when performed on "indeterminate" nodules. However, the more updated tools that can be used to this purpose in order to "rule out" (Afirma GSC) or "rule in" (Thyroseq v3) malignancy, have a main limitation: the high costs. In the last years various image-guided procedures have been proposed as alternative and less invasive approaches to surgery for symptomatic thyroid nodules. These minimally invasive techniques (laser and radio-frequency ablation, high intensity focused ultrasound and percutaneous microwave ablation) results in nodule shrinkage and improvement of local symptoms, with a lower risk of complications and minor costs compared to surgery. Finally, ultrasound-guided ablation therapy was introduced with promising results as a feasible treatment for low-risk papillary thyroid microcarcinoma or cervical lymph node metastases.

Qualitative and Semiquantitative Elastography for the Diagnosis of Intermediate Suspicious Thyroid Nodules Based on the 2015 American Thyroid Association Guidelines

OBJECTIVES

To evaluate qualitative and semiquantitative elastography for the diagnosis of intermediate suspicious thyroid nodules based on the 2015 American Thyroid Association (ATA) guidelines.

METHODS

Through a retrospective search of our institutional database, 746 solid thyroid nodules found on grayscale ultrasonography, strain elastography, and ultrasound-guided fine-needle aspiration between June and November 2009 were collected. Among them, 80 nodules from 80 patients with an intermediate suspicion of malignancy based on the 2015 ATA guidelines that were 10 mm or larger were recruited as the final study nodules. Elastographic findings were categorized according to the criteria of Rago et al (J Clin Endocrinol Metab 2007; 92:2917-2922) and Asteria et al (Thyroid 2008; 18:523-531), and strain ratio values were calculated and recorded. The independent 2-sample t test and χ² test (or Fisher exact test) were used to evaluate differences in clinical parameters between benign and malignant thyroid nodules. All variables were compared by univariate and multivariate logistic regression analyses, and odds ratios with 95% confidence intervals were calculated.

RESULTS

Of the 80 nodules, 6 (7.5%) were malignant, and 74 (92.5%) were benign. No significant differences were observed in age, sex, nodule size, elasticity score, and strain ratio between benign and malignant nodules. No variables significantly predicted thyroid malignancy on the univariate analysis. On the multivariate logistic regression analysis, there were no independent variables associated with thyroid malignancy, including the elasticity score and strain ratio (all P > .05).

CONCLUSIONS

Elastographic analysis using the elasticity score and strain ratio has limited ability to characterize the benignity or malignancy of thyroid nodules with an intermediate suspicion of malignancy based on the 2015 ATA guidelines.

Does Lesion Size Affect the Value of Shear Wave Elastography for Differentiating Between Benign and Malignant Thyroid Nodules?

OBJECTIVES

We aimed to investigate the diagnostic performance of shear wave elastography (SWE) combined with conventional ultrasonography (US) for differentiating between benign and malignant thyroid nodules of different sizes.

METHODS

A total of 445 thyroid nodules from 445 patients were divided into 3 groups based on diameter (group 1, ≤ 10 mm; group 2, 10-20 mm; and group 3, > 20 mm). The mean elasticity index of the whole lesion was automatically calculated, and the threshold for differentiation between benign and malignant nodules was constructed by a receiver operating characteristic curve analysis. Diagnostic performances of conventional US and SWE were compared by using pathologic results as reference standards.

RESULTS

The mean elasticity was significantly higher in malignant versus benign nodules for all size groups. The differences in mean elasticity in the size groups were not statistically significant for malignant or benign nodules. The specificity of US combined with SWE for group 1 was significantly higher than that for groups 2 and 3 (77.8% versus 62.9% and 53.3%; P < .05), and compared with group 1, the sensitivity was significantly higher for groups 2 and 3 (92.4% and 94.3% versus 80.7%; P < .05). When SWE was added, the specificity increased and the sensitivity and diagnostic accuracy decreased for group 1, and the sensitivity increased and the specificity decreased for groups 2 and 3; however, the differences were not significant.

CONCLUSIONS

Combined with SWE, US yielded higher specificity for nodules of 10 mm and smaller and higher sensitivity for nodules larger than 10 mm.

Ultrasonographic features and clinicopathologic characteristics of macrofollicular variant papillary thyroid carcinoma

Macrofollicular variant papillary thyroid carcinoma (MFV-PTC) is defined as papillary thyroid carcinoma with macrofollicles of >200 μm in more than 50% of the cross-sectional area of the specimen. The aim of this study was to evaluate the clinicopathologic characteristics of the MFV-PTC treated in the Yonsei University College of Medicine.Between September 2007 and July 2012, 18,697 patients with PTC were treated in our institution. Of these, 10 patients (0.05%) were diagnosed as the MFV-PTC in final pathologic report.Mean age of 10 patients were 42.5 years old, ranging from 26 to 69 years. Twelve lesions were found in 10 patients. On preoperative ultrasonographic examination, most of tumors looked like benign nodules. The tumor nodules varied in size from 0.3 to 3.5 cm in greatest dimension. Microscopically, the macrofollicles were surrounded by cuboidal cells with hyperchromatic nuclei and occupied entire nodule.MFV-PTC showed the benign appearance in ultrasonography. To avoid misdiagnosis of MFV-PTC, clinicians should be aware of the characteristics of MFV-PTC and perform ultrasonography with fine needle aspiration biopsy appropriately.

Combination of Sonoelastography and TIRADS for the Diagnostic Assessment of Thyroid Nodules

To evaluate the diagnostic performance of elastography alone and combined with Thyroid Imaging Reporting And Data System (TIRADS) for the assessment of non-autonomous thyroid nodules. We included 244 thyroid nodules and analyzed the visual elasticity scores, strain value (SV) and TIRADS classification. Histologic examination revealed 38 malignant (16%) and 206 benign nodules. The SV was lower in malignant nodules than in benign with an optimal cutoff ≤0.225. The visual elasticity scores showed a better diagnostic performance than the SV measurement. The risk for malignancy increased with higher TIRADS category. The sensitivity, specificity, positive predictive value and negative predictive value of TIRADS were superior to sonoelastography. The combination of TIRADS ≥4C and SV ≤0.225 showed the highest odds ratio to predict malignancy. Kwak-TIRADS classification is superior to elastography for the differentiation of benign and malignant thyroid nodules. Our data demonstrate that a high TIRADS class alone is predictive for thyroid carcinoma and the clinical relevance of sonoelastography is negligible.

Tall cell variant of papillary thyroid carcinoma: current evidence on clinicopathologic features and molecular biology

Tall cell variant (TCV) of papillary thyroid carcinoma (PTC) has been recognized for the past few decades as an entity showing aggressive biological behavior; however, there is considerable controversy regarding the definition, clinical and pathological features of TCV because of its rarity and difficult diagnosis. No clinical features can accurately diagnose TCV. Thus, the results of histocytology, immunohistochemistry and molecular genetics tests have important clinical implications for diagnosis. Given the aggressiveness and the increased recurrence and poor survival rates, more aggressive treatment approach and rigorous follow-up is required for patients with TCV. In the present article, we undertook a comprehensive review to summarize and discuss the various aspects of this variant, from morphology to immunohistochemistry, and molecular abnormalities from a practical and daily practice-oriented point of view.

H-scan analysis of thyroid lesions

The H-scan analysis of ultrasound images is a matched-filter approach derived from analysis of scattering from incident pulses in the form of Gaussian-weighted Hermite polynomial functions. This framework is applied in a preliminary study of thyroid lesions to examine the H-scan outputs for three categories: normal thyroid, benign lesions, and cancerous lesions within a total group size of 46 patients. In addition, phantoms comprised of spherical scatterers are analyzed to establish independent reference values for comparison. The results demonstrate a small but significant difference in some measures of the H-scan channel outputs between the different groups.

A Systematic Investigation of Lateral Estimation Using Various Interpolation Approaches in Conventional Ultrasound Imaging

Accurate lateral displacement and strain estimation is critical for some applications of elasticity imaging. Typically, motion estimation in the lateral direction is challenging because of low sampling frequency and lack of phase information in conventional ultrasound imaging. Several approaches have been proposed to improve the performance of lateral estimation, such as lateral interpolation on the radio frequency (RF) signals (Interp_RF), lateral interpolation on the cross-correlation function (Interp_CCF), and lateral interpolation on both the RF signals and cross-correlation function (Interp_Both). In this paper, the estimation performances of the above-mentioned three approaches are compared systematically in simulations and phantom experiments. In the simulations, the root-mean-square error (RMSE) of axial/lateral displacement and strain is utilized to assess the accuracy of motion estimation. In the phantom experiments, the displacement quality metric (DQM), defined as the normalized cross-correlation between the motion-compensated reference frame and the comparison frame, and the contrast-to-noise ratio (CNR) of axial/lateral strain are used as the evaluation criteria. The results show that the three approaches have similar performance in axial estimation. For lateral estimation, if the line density of ultrasound imaging is relatively high (i.e., >4.2 lines/mm), Interp_CCF is comparable to Interp_Both, and Interp_RF performs the worst. However, if the line density is relatively low (i.e., <2.8 lines/mm), Interp_Both performs the best as indicated by the lowest RMSEs or highest DQMs and CNRs in lateral estimation. The trend is consistent at different window sizes, applied strains, and sonographic signal-to-noise ratios (>20 dB). Besides, Interp_Both with a small interpolation factor (e.g., 3-5) is found to obtain the best tradeoff between the estimation accuracy and the computational cost, and thus is suggested for lateral motion estimation in the case of a low line density (i.e., <2.8 lines/mm).

US Elastography Using Carotid Artery Pulsation May Increase the Diagnostic Accuracy for Thyroid Nodules with US-Pathology Discordance

This study evaluated the diagnostic performance of ultrasound elastography (USE) using carotid arterial pulsation and determined the reproducibility of USE for thyroid nodules. A total of 148 patients with 173 thyroid nodules participated. The mean elasticity contrast index (ECI) was significantly higher in malignant nodules (3.1 ± 1.5) than in benign nodules (1.7 ± 0.8) (p < 0.001). When a cut-off ECI value of 3.5 was used, the diagnostic accuracy (78.6%) of gray-scale ultrasound (US) + ECI was the highest compared with that of the gray-scale US (76.9%) and ECI (67.1%). In 16 of 43 nodules (37.2%) with US-pathology, discordance could be correctly reclassified as benign (8 of 11) or malignant (8 of 32). The intra-class correlation coefficient for inter-observer agreement was 0.96, and those for intra-observer agreement were 0.97 and 0.98. Thyroid nodules with ECI values of >3.5 may have an additional value to increase the diagnostic accuracy for nodules with US-pathology discordance with reproducible results.

Diagnostic value of strain elastography for differentiating benign and malignant soft tissue masses

The aim of the current study was to investigate the importance of strain elastography (SE) in the differential diagnosis of benign and malignant soft tissue masses. SE was adopted to examine 61 patients with superficial masses, classify their elastic scores and assess their strain ratios (SRs) between the masses and the surrounding structures. Significantly increased SR values and elastic scores were observed in the malignant masses compared with the benign masses (5.42±3.47 vs. 1.80±2.10, P<0.001; 3.13±0.34 vs. 2.03±0.99, P<0.001). Area under receiver operating characteristic curve values of the SRs and elastic scores were 0.87 (P<0.001) and 0.805 (P=0.001), respectively. With an SR of >2.295 as the optimal threshold value, the sensitivity, specificity and positive and negative predictive values for diagnosing a malignant mass were 93.8, 80.5, 65.2 and 97.1%, respectively; whilst using an elastic score of ≥3 as the optimal threshold value, the sensitivity, specificity and positive and negative predictive values for diagnosing a malignant mass were 100, 51.6, 51.6 and 100%, respectively. SR values and elastic scores were significantly different between the malignant and benign soft tissue masses. Therefore, SE may be used to effectively differentiate between malignant and benign soft tissue masses.

Current status of musculoskeletal application of shear wave elastography

Ultrasonography (US) is a very powerful diagnostic modality for the musculoskeletal system due to the ability to perform real-time dynamic high-resolution examinations with the Doppler technique. In addition to acquiring morphologic data, we can now obtain biomechanical information by quantifying the elasticity of the musculoskeletal structures with US elastography. The earlier diagnosis of degeneration and the ability to perform follow-up evaluations of healing and the effects of treatment are possible. US elastography enables a transition from US-based inspection to US-based palpation in order to diagnose the characteristics of tissue. Shear wave elastography is considered the most suitable type of US elastography for the musculoskeletal system. It is widely used for tendons, ligaments, and muscles. It is important to understand practice guidelines in order to enhance reproducibility. Incorporating viscoelasticity and overcoming inconsistencies among manufacturers are future tasks for improving the capabilities of US elastography.

Elastography in Distinguishing Benign from Malignant Thyroid Nodules

AIM

The aim of this study is to test the diagnostic success of strain elastography in distinguishing benign from malignant thyroid nodules.

MATERIALS AND METHODS

The size, echogenicity, and halo integrity of 293 thyroid nodules and the presence of microcalcification in these nodules were evaluated on gray-scale examination. Doppler characteristics and elastography patterns were also evaluated and recorded. Nodules were classified in four categories (patterns 1-4) based on elastographic examination.

RESULTS

According to the cytopathological findings, 222 nodules were benign, and 71 nodules were malignant. The risk of a nodule to be malignant was 3.8 times increased by hypoechogenicity, 7.7 times increased by the presence of microcalcification, and 11.5 times increased by the absence of halo. On Doppler patterns, the presence of central vascularity increased the malignancy risk of a nodule by 5.8 times. According to the receiver operating characteristic analysis, patterns 3 and 4 were malignant, and patterns 1 and 2 were benign. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of elastography were 100%, 80.2%, 61.7%, 100%, and 85%, respectively.

CONCLUSION

Strain elastography can be used as a noninvasive method in distinguishing benign from malignant thyroid nodules and in identifying the patients who would undergo surgery.

Core-needle biopsy versus repeat fine-needle aspiration for thyroid nodules initially read as atypia/follicular lesion of undetermined significance

BACKGROUND

The purpose of this study was to evaluate the role of core-needle biopsy (CNB) by comparing the results of CNB and repeat fine-needle aspiration (FNA) for thyroid nodules that are initially read as atypia/follicular lesion of undetermined significance (AUS/FLUS) on FNA.

METHODS

Among 2631 initial AUS/FLUS FNA results, 505 consecutive nodules (295 repeat FNAs and 210 CNBs) were retrospectively analyzed. The primary outcome was inconclusive (ie, nondiagnostic or AUS/FLUS). The secondary outcomes included inconclusive results of the subcategory, risk factors for inconclusive results, and diagnostic performance.

RESULTS

CNB demonstrated significantly fewer inconclusive results than repeat FNA for the overall nodules (40.9% vs 63%; p < .001). Repeat FNA and group FLUS were significant risk factors for inconclusive results (odds ratio = 1.92; p =.001 and odds ratio = 2.08; p <.001, respectively). All diagnostic performances using CNB were higher than repeat FNAs.

CONCLUSION

CNB is more useful than repeat FNAs for reducing inconclusive results and improving the diagnostic performance of thyroid nodules with initial AUS/FLUS FNA results. © 2016 Wiley Periodicals, Inc. Head Neck 39: 361-369, 2017.

Clinical photoacoustic imaging of cancer

Photoacoustic imaging is a hybrid technique that shines laser light on tissue and measures optically induced ultrasound signal. There is growing interest in the clinical community over this new technique and its possible clinical applications. One of the most prominent features of photoacoustic imaging is its ability to characterize tissue, leveraging differences in the optical absorption of underlying tissue components such as hemoglobin, lipids, melanin, collagen and water among many others. In this review, the state-of-the-art photoacoustic imaging techniques and some of the key outcomes pertaining to different cancer applications in the clinic are presented.

Amyloidosis of the liver on shear wave elastography: case report and review of literature

Amyloidosis is extremely rare, with an estimated 2225 new US cases reported annually. Signs and symptoms of the disease are subtle and imaging findings are not pathognomonic. Currently, diagnosis requires biopsy to demonstrate the deposition of amyloid. Elastography is a new imaging modality that evaluates tissue elasticity. It has shown to have efficacy in characterizing thyroid nodules, detecting prostate cancer, and staging liver fibrosis. We present a case of hepatic amyloidosis in a 51-year-old male that demonstrates significantly increased stiffness with a median value of 99.1 kPa (range 25.7-188.9 kPa) on shear-wave elastography (SWE) imaging, which is significantly higher than the cut-off range reported for cirrhosis on SWE (10.4-11.5 kPa). This finding raises the possibility that elastographic imaging may be sensitive to tissue mechanical changes induced by amyloid deposition.

Avoidance of unnecessary fine-needle aspiration with the use of the Thyroid Imaging Reporting Data System classification and strain elastography based on The Bethesda System for Reporting Thyroid Cytopathology

Thyroid fine-needle aspiration (FNA) biopsy has been widely accepted as an accurate and cost-effective tool in the management of thyroid nodules. To avoid unnecessary FNAs and provide appropriate management, patient evaluation should be based on a multidisciplinary approach. For this purpose, the Thyroid Imaging Reporting and Data System (TI-RADS) and strain elastography (SE) were proposed as tools for the risk assessment of malignancy in thyroid nodules. The aim of the present study was to analyze the utility of TI-RADS system and SE, along with FNA, and prospectively evaluate 369 consecutive patients referred for FNA of a thyroid nodule. TI-RADS was tested against The Bethesda System for Reporting Thyroid Cytopathology to determine whether there was an agreement between the two classification systems; statistically, some agreement was observed. Medians of the maximum SE values (E-max) were obtained for benign and malignant FNA results and found to be 1.97 [interquartile range (IQR): 1.87] and 2.8 (IQR: 3.42), respectively (P=0.004). The number of studies investigating the utility of TI-RADS and SE along with TBSRCT is currently limited. Our study demonstrated that a multidisciplinary approach with the use of TI-RADS and SE may mildly improve the management of thyroid nodules.

Contrast-enhanced ultrasound and real-time elastography in the differential diagnosis of malignant and benign thyroid nodules

The diagnostic value of contrast-enhanced ultrasound (CEUS) or real-time elastography (RTE) alone, as well as a combination of CEUS and RTE, in distinguishing benign from malignant thyroid nodules was investigated. Between August 2012 and June 2014, a total of 97 consecutive patients (50 male and 47 female patients; mean age, 48.6±12.4; age range, 27-70 years) with thyroid nodules referred for surgical treatment were examined by CEUS and RTE. The final diagnosis was obtained based on histological findings. Image analysis of the CEUS and RTE scans was performed. Considering the postoperative pathological results as the golden standard, a receiver operating characteristic (ROC) curve was constructed. Subsequently, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of CEUS alone, RTE alone and CEUS + RTE combination were calculated. Pathological examination showed 66 papillary carcinomas and 43 benign lesions, including 21 adenomas and 22 nodular goiters. The sensitivity, specificity, PPV, NPV and accuracy of CEUS were 81.82, 90.70, 93.10, 90.70 and 85.32%, respectively. In the case of RTE, the sensitivity, specificity, PPV, NPV and accuracy were 80.30, 88.37, 91.38, 88.37 and 83.49%, respectively. Furthermore, the combination of CEUS + RTE had a sensitivity of 95.45%, specificity of 95.35%, PPV of 96.92%, NPV of 95.35% and accuracy of 95.41%. Therefore, the CEUS + RTE combination showed a significantly higher sensitivity and specificity compared with CEUS or RTE alone (all P<0.05). Based on ROC analysis, the area under the curve (AUC) for CEUS, RTE and CEUS + RTE combination was 0.883, 0.863 and 0.959, respectively. The AUC of RTE alone was significantly lower compared with that of the CEUS + RTE combination. In conclusion, our results demonstrate that CEUS + RTE combination significantly increases the diagnostic performance for differential diagnosis of malignant and benign thyroid nodules compared with CEUS or RTE alone.

Ultrasonography Diagnosis and Imaging-Based Management of Thyroid Nodules: Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations

The rate of detection of thyroid nodules and carcinomas has increased with the widespread use of ultrasonography (US), which is the mainstay for the detection and risk stratification of thyroid nodules as well as for providing guidance for their biopsy and nonsurgical treatment. The Korean Society of Thyroid Radiology (KSThR) published their first recommendations for the US-based diagnosis and management of thyroid nodules in 2011. These recommendations have been used as the standard guidelines for the past several years in Korea. Lately, the application of US has been further emphasized for the personalized management of patients with thyroid nodules. The Task Force on Thyroid Nodules of the KSThR has revised the recommendations for the ultrasound diagnosis and imaging-based management of thyroid nodules. The review and recommendations in this report have been based on a comprehensive analysis of the current literature and the consensus of experts.