[Elastosonography of thyroid lesions]

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.

Shear-wave elastography combined with contrast-enhanced ultrasound algorithm for noninvasive characterization of focal liver lesions

PURPOSE

To establish shear-wave elastography (SWE) combined with contrast-enhanced ultrasound (CEUS) algorithm (SCCA) and improve the diagnostic performance in differentiating focal liver lesions (FLLs).

MATERIAL AND METHODS

We retrospectively selected patients with FLLs between January 2018 and December 2019 at the First Affiliated Hospital of Sun Yat-sen University. Histopathology was used as a standard criterion except for hemangiomas and focal nodular hyperplasia. CEUS with SonoVue (Bracco Imaging) and SCCA combining CEUS and maximum value of elastography with < 20 kPa and > 90 kPa thresholds were used for the diagnosis of FLLs. The diagnostic performance of CEUS and SCCA was calculated and compared.

RESULTS

A total of 171 FLLs were included, with 124 malignant FLLs and 47 benign FLLs. The area under curve (AUC), sensitivity, and specificity in detecting malignant FLLs were 0.83, 91.94%, and 74.47% for CEUS, respectively, and 0.89, 91.94%, and 85.11% for SCCA, respectively. The AUC of SCCA was significantly higher than that of CEUS (P = 0.019). Decision curves indicated that SCCA provided greater clinical benefits. The SCCA provided significantly improved prediction of clinical outcomes, with a net reclassification improvement index of 10.64% (P = 0.018) and integrated discrimination improvement of 0.106 (P = 0.019). For subgroup analysis, we divided the FLLs into a chronic-liver-disease group (n = 88 FLLs) and a normal-liver group (n = 83 FLLs) according to the liver background. In the chronic-liver-disease group, there were no differences between the CEUS-based and SCCA diagnoses. In the normal-liver group, the AUC of SCCA and CEUS in the characterization of FLLs were 0.89 and 0.83, respectively (P = 0.018).

CONCLUSION

SCCA is a feasible tool for differentiating FLLs in patients with normal liver backgrounds. Further investigations are necessary to validate the universality of this algorithm.

Diagnostic Performance of Ultrasound Strain Elastography in Transverse and Longitudinal Views in Predicting Malignant Thyroid Nodules

Agreement between ultrasound strain elastography (SE) scores of transverse and longitudinal views of thyroid nodules was investigated, and the diagnostic performance of these scores in predicting thyroid malignancy was assessed. From December 2016 to February 2017, a total of 250 thyroid nodules in 232 patients (62 males and 188 females, mean age: 45 y [20-75 y]) were enrolled. Diagnostic agreement between SE scores obtained in different views was assessed. Sensitivity, specificity, area under the receiver operating characteristic curve (Az) of the SE score in different criteria (criterion 1, SE score ≥4 from any view is defined as suspicious; criterion 2, SE score ≥4 as in only transverse view; and criterion 3, SE score ≥4 only from longitudinal view) were evaluated. Diagnostic agreement between SE scores of different views was fair (κ = 0.227). The Az value for criterion 1 (0.770, 95% confidence interval [CI]: 0.713, 0.820) was the highest among the three criteria, significantly higher than that of criterion 2 (0.692, 95% CI: 0.631, 0.749) (p < 0.001), but not statistically significantly different from that of criterion 3 (0.768, 95% CI: 0.711, 0.819) (p = 0.909). However, the Az value for criterion 3 was higher than that for criterion 2 (p < 0.005). The results indicated that criterion 1 had high sensitivity (80.0%) and criterion 2 had high specificity (68.0%). Our study found that the agreement between SE scores of different views was fair. SE scores ≥4 in either view were most sensitive for predicting malignant thyroid nodules.

Comparative Diagnostic Accuracy of Contrast-Enhanced Ultrasound and Shear Wave Elastography in Differentiating Benign and Malignant Lesions: A Network Meta-Analysis

Background: We performed a network meta-analysis to compare the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) and shear wave elastography (SWE) in differentiating benign and malignant lesions in different body sites.

Methods: A computerized literature search of Medline, Embase, SCOPUS, and Web of Science was performed using relevant keywords. Following data extraction, we calculated sensitivity, specificity, positive likelihood ratio (LR), negative LR, and diagnostic odds ratio (DOR) for CEUS, and SWE compared to histopathology as a reference standard. Statistical analyses were conducted by MetaDiSc (version 1.4) and R software (version 3.4.3).

Results: One hundred and fourteen studies (15,926 patients) were pooled in the final analyses. Network meta-analysis showed that CEUS had significantly higher DOR than SWE (DOR = 27.14, 95%CI [2.30, 51.97]) in breast cancer detection. However, there were no significant differences between CEUS and SWE in hepatic (DOR = −6.67, 95%CI [−15.08, 1.74]) and thyroid cancer detection (DOR = 3.79, 95%CI [−3.10, 10.68]). Interestingly, ranking analysis showed that CEUS achieved higher DOR in detecting breast and thyroid cancer, while SWE achieved higher DOR in detecting hepatic cancer. The overall DOR for CEUS in detecting renal cancer was 53.44, 95%CI [29.89, 95.56] with an AUROC of 0.95, while the overall DOR for SWE in detecting prostate cancer was 25.35, 95%CI [7.15, 89.89] with an AUROC of 0.89.

Conclusion: Both diagnostic tests showed relatively high sensitivity and specificity in detecting malignant tumors in different organs. Network meta-analysis showed that CEUS had higher diagnostic accuracy than SWE in detecting breast and thyroid cancer, while SWE had higher accuracy in detecting hepatic cancer. However, the results were not statistically significant in hepatic and thyroid malignancies. Further head-to-head comparisons are needed to confirm the optimal imaging technique to differentiate each cancer type.

Clinical efficacy of novel elastography using acoustic radiation force impulse (ARFI) for diagnosis of malignant thyroid nodules

Objective

Acoustic radiation force impulse (ARFI) imaging is a recent ultrasound elastography technique; consequently, its efficacy is not fully known. In this study, we compared ARFI imaging with conventional strain elastography (SE) and shear wave velocities (SWVs) to evaluate the utility of ARFI imaging for diagnosing thyroid nodules.

Subjects and Methods

In this study we examined 233 thyroid nodules (183 benign nodules and 50 malignant nodules) isolated from human patients. The nodules were evaluated with SE and ARFI imaging, and SWVs of the nodules were simultaneously measured. ARFI images were classified using a four‐point score based on grayscale intensity of the images. The sensitivity, specificity, and diagnostic accuracy were compared between SE and ARFI imaging. Finally, SWVs for each score of SE and ARFI imaging were compared.

Results

The new scoring system for ARFI imaging can be divided into four virtual touch imaging (VTI) scores. Nodules with a VTI score of 3 or 4 as determined by ARFI imaging were determined to be malignant. The sensitivity, specificity, and diagnostic accuracy, respectively, were 63.2%, 66.3%, and 65.6% for SE, compared with 80.0%, 86.3%, and 85.0% for ARFI imaging. The median SWVs of the nodules were 1.57 m/s, 1.73 m/s, 1.88 m/s, and 2.09 m/s for VTI scores of 1, 2, 3, and 4, respectively. The SWVs of VTI scores 3 and 4 were significantly higher than those of VTI scores 1 and 2.

Conclusions

The diagnostic accuracy of ARFI imaging for differentiating malignant thyroid nodules was higher than that of SE. The VTI scores of the nodules accurately reflected their SWVs.

Level of Evidence

4

Can Ultrasound Alone Predict Papillary Thyroid Carcinoma with Desmoid-Type Fibromatosis? A Retrospective Analysis of 13 Cases, Focusing on the Stromal Area

Purpose

Papillary thyroid carcinoma with desmoid-type fibromatosis (PTC-DTF) is extremely rare. So far, only 4 cases describing the ultrasound findings of this variant have been reported. Here, we describe the ultrasound findings of 13 cases of PTC-DTF, focusing especially on the DTF area.

Materials and Methods

We retrospectively analyzed the clinical reports, ultrasound reports, and ultrasound photographs obtained from medical records at Kuma Hospital.

Results

The patients included 8 women and 5 men with a mean age of 47.9 years. The widest dimension of the nodules ranged from 16 to 79 mm (mean: 37.5 mm). The original ultrasound reports classified the nodules as either intermediate suspicion or high suspicion. A diagnosis of PTC was suspected in 12 nodules, and anaplastic carcinoma was suspected in 1 nodule. PTC-DTF presented with an irregularly shaped nodule (100%), taller-than-wide sign (84.6%), heterogeneous echogenicity (100%), no microcalcification (76.9%), and no or mild flow signal on Doppler (75.0%). The DTF area was identified in the ultrasound photographs of 8 nodules. DTF areas were generally heterogeneous (62.5%) and more hypoechoic (71.4%) than PTC areas. Microcalcification was not observed in the DTF areas. All of the DTF areas revealed no or mild flow signal. On ultrasound elastography, the DTF areas were not stiff, and they were more elastic than the PTC areas.

Conclusion

It is difficult to predict PTC-DTF using ultrasound alone, and B-mode ultrasonography is more reliable than ultrasound elastography in the ultrasound diagnosis of malignant thyroid nodules.

Strain elastography of tongue carcinoma using intraoral ultrasonography: A preliminary study to characterize normal tissues and lesions

Purpose

The aim of this study was to evaluate the quantitative strain elastography of tongue carcinoma using intraoral ultrasonography.

Materials and Methods

Two patients with squamous cell carcinoma (SCC) who underwent quantitative strain elastography for the diagnosis of tongue lesions using intraoral ultrasonography were included in this prospective study. Strain elastography was performed using a linear 14 MHz transducer (Aplio 300; Canon Medical Systems, Otawara, Japan). Manual light compression and decompression of the tongue by the transducer was performed to achieve optimal and consistent color coding. The variation in tissue strain over time caused by the compression exerted using the probe was displayed as a strain graph. The integrated strain elastography software allowed the operator to place circular regions of interest (ROIs) of various diameters within the elastography window, and automatically displayed quantitative strain (%) for each ROI. Quantitative indices of the strain (%) were measured for normal tissues and lesions in the tongue.

Results

The average strain of normal tissue and tongue SCC in a 50-year-old man was 1.468% and 0.000%, respectively. The average strain of normal tissue and tongue SCC in a 59-year-old man was 1.007% and 0.000%, respectively.

Conclusion

We investigated the quantitative strain elastography of tongue carcinoma using intraoral ultrasonography. Strain elastography using intraoral ultrasonography is a promising technique for characterizing and differentiating normal tissues and SCC in the tongue.

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

OBJECTIVES

To evaluate the diagnostic performance of Virtual Touch tissue imaging quantification (VTIQ; Siemens Medical Solutions, Mountain View, CA) in combination with the Thyroid Imaging Reporting and Data System (TI-RADS) for assessing thyroid nodules referred for biopsy.

METHODS

A total of 197 surgically or cytologically proven thyroid nodules in 187 patients were included. Nodules evaluated by conventional ultrasound (US) and VTIQ examinations were classified into US TI-RADS categories. The shear wave velocity (SWV) on VTIQ was assessed, and the cutoff value was obtained from a receiver operating characteristic curve analysis. Diagnostic performances of conventional US, VTIQ, and their combination were compared.

RESULTS

There were 134 benign and 63 malignant nodules. The sensitivity and specificity for the US TI-RADS were 98.4% and 20.1%, respectively. The areas under the receiver operating characteristic curves for the mean, maximum, minimum, and ratio of the SWV were 0.818, 0.805, 0.799, and 0.728. With a cutoff value of 2.90 m/s, the sensitivity and specificity of the mean SWV were 71.4% and 82.8%. By applying this value or less as a standard for downgrading TI-RADS category 4a to category 3 lesions, the specificity significantly rose from 20.1% to 47.0% (P < .001) without a loss of sensitivity.

CONCLUSIONS

The additional application of VTIQ can improve the specificity of the TI-RADS for evaluating thyroid nodules without a loss of sensitivity.

Strain Elastography - How To Do It?

Tissue stiffness assessed by palpation for diagnosing pathology has been used for thousands of years. Ultrasound elastography has been developed more recently to display similar information on tissue stiffness as an image. There are two main types of ultrasound elastography, strain and shear wave. Strain elastography is a qualitative technique and provides information on the relative stiffness between one tissue and another. Shear wave elastography is a quantitative method and provides an estimated value of the tissue stiffness that can be expressed in either the shear wave speed through the tissues in meters/second, or converted to the Young's modulus making some assumptions and expressed in kPa. Each technique has its advantages and disadvantages and they are often complimentary to each other in clinical practice. This article reviews the principles, technique, and interpretation of strain elastography in various organs. It describes how to optimize technique, while pitfalls and artifacts are also discussed.

Application of high-resolution ultrasound, real-time elastography, and contrast-enhanced ultrasound in differentiating solid thyroid nodules

High-resolution ultrasound (HRUS) is a sensitive tool for identifying thyroid nodules. Real-time elastography (RTE) and contrast-enhanced ultrasound (CEUS) are newly developed methods which could measure tissue elasticity and perfusion features. The aim of the present study was to evaluate and compare the diagnostic efficiency of HRUS, RTE, CEUS and their combined use in the differentiation of benign and malignant solid thyroid nodules.In total, 111 consecutive patients with 145 thyroid nodules who were scheduled for surgery were included in the study. All of them underwent HRUS, RTE, and CEUS examination. The independent ultrasound (US) predictors for malignancy were determined and quantified using logistic regression analysis, based on which a risk-scoring model was established for each method. The diagnostic efficiency of each method was assessed by receiver operating characteristic (ROC) curve analysis.HRUS showed the best diagnostic efficiency among the 3 US methods, with 74.6% sensitivity and 87.8% specificity. CEUS had higher sensitivity (85.7%), whereas RTE alone did not show much advantage. Combined use of RTE and HRUS increased the sensitivity (92.1%). The HRUS-RTE-CEUS combination could increase both the sensitivity and specificity (87.3%, 91.5%), with the best AUC (0.935) among all the methods.The overall diagnostic value of HRUS in predicting malignancy is the best among the 3 US methods. Combined use of RTE and CEUS and HRUS could improve the diagnostic efficiency for solid thyroid nodules.

Diagnostic performance of elastography in cytologically indeterminate thyroid nodules

Cytological examination of material from fine-needle aspiration biopsy is the mainstay of diagnosis of thyroid nodules, thanks to its remarkable accuracy and scarcity of complications. However, follicular lesions (also called indeterminate lesions or Thy3 in the current classification), a heterogeneous group of lesions in which cytology is unable to give a definitive diagnosis to, represent its main limit. Elastography has been proposed as a potential diagnostic tool to define the risk of malignancy in the aforementioned nodules, but at present there is no conclusive data due to the small number of specifically addressed studies and the lack of concordance among them. The objective of our study was to evaluate the role of real-time elastography (RTE) for refining diagnosis of Thy3 nodules, by integrating diagnostic information provided by traditional ultrasound (US). The study included 108 patients with Thy3 nodules awaiting for surgery, which were evaluated by US (considering hypoecogenicity, irregular margins, microcalcifications, halo sign, and intranodular vascularization) and RTE. Nodules were classified at RTE using a four-class color scale. At histologic examination, 75 nodules were benign and 33 malignant. As expected, none of the ultrasound parameters alone was adequate in predicting malignancy or benignity of the nodules; in the presence of at least two US risk factors, we obtained 61 % sensitivity, 83 % specificity, and 77 % accuracy with 6.8 OR (95 % CI 2.4-20.4). RTE scores 3 and 4 showed 76 % sensitivity, 88 % specificity, 74 % PPV, and 89 % NPV with diagnostic accuracy of 84 %; the data are statistically significant (p < 0.0001) with a OR of 21.9 (95 % CI 7.1-76). By combining RTE with US parameters, the presence of at least 2 characters of suspicion had 88 % sensitivity and 94 % NPV with 23.8 OR (95 % CI 7-106.3). The use of combined RTE and US leads to the identification of two patients subpopulations which have a significantly different malignancy risk (6 vs. 63 %); further studies are needed to verify if it is possible to send only the first group to thyroidectomy and the other to follow-up.

Acoustic radiation force impulse elastography for differentiation of benign and malignant thyroid nodules with concurrent Hashimoto's thyroiditis

The purpose of the study was to explore the diagnostic performance of acoustic radiation force impulse (ARFI) elastography in differential diagnosis between benign and malignant thyroid nodules in patients with coexistent Hashimoto's thyroiditis (HT). A total of 141 pathological proven nodules in 141 HT patients (7 males and 134 females, mean age 50.1 years, range 23-75 years) received conventional ultrasound (US), elasticity imaging (EI) and ARFI elastography, including virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ), before surgery. Shear wave velocity (SWV) and SWV ratio were measured for each nodule on VTQ. The US, EI and ARFI elastography features were compared between benign and malignant nodules in HT patients. Receiver operating characteristic curve (ROC) analyses and area under curve (AUC) were performed to assess the diagnostic performance. Pathologically, 70 nodules were benign and 71 nodules were malignant. Significant differences were found between benign and malignant nodules in HT patients for EI (EI score) and ARFI (VTI grade and SWV) (all P value <0.05). The AUCs for EI, VTI, SWV and SWV ratio were 0.68 [95% confidence interval (CI): 0.59-0.77], 0.90 (95% CI: 0.84-0.95), 0.77 (95%CI: 0.70-0.85) and 0.74 (95%CI: 0.66-0.82), respectively. The cut-off points were EI score ≥3, VTI grade ≥4, SWV ≥2.58 m/s and SWV ratio ≥1.03, respectively. In conclusion, ARFI elastography is useful for differentiation between benign and malignant thyroid nodules in HT patients. The diagnostic performance of ARFI elastography is better than EI.

Qualitative elastography can replace thyroid nodule fine-needle aspiration in patients with soft thyroid nodules. A systematic review and meta-analysis

CONTEXT

Only a minority of thyroid nodules is malignant; nevertheless, many invasive diagnostic procedures are performed to distinguish between benign and malignant nodules. Qualitative ultrasound elastography is a non-invasive technique to evaluate thyroid nodules.

OBJECTIVE

To investigate the diagnostic value of qualitative elastography in distinguishing benign from malignant thyroid nodules in patients referred for fine-needle aspiration (FNA).

DATA SOURCES

A systematic literature search (PubMed, Embase and Cochrane Library) was performed.

STUDY SELECTION

Included studies reported thyroid nodule elastography color scores and the related cytologic or histologic findings in patients with a thyroid nodule referred for FNA.

DATA EXTRACTION

Two independent reviewers extracted study data and assessed study quality. Pooled sensitivities and specificities of different populations were calculated using a bivariate Bayesian framework.

DATA SYNTHESIS

Twenty studies including thyroid nodules were analyzed. Pooled results of elastography indicate a summary sensitivity of 85% (95% confidence interval [CI], 79-90%) and specificity of 80% (95% CI, 73-86%). The respective pooled negative predictive and positive predictive values were 97% (95% CI, 94-98%) and 40% (95% CI, 34-48%). The pretest probability of a benign nodule was 82%. Only 3.7% of the false-negative nodules was a follicular thyroid carcinoma. A pooled negative predictive value of 99% (95% CI, 97-100%) was found when only complete soft nodules (Asteria elastography 1) were classified as benign, which included 14% of the studied population.

CONCLUSIONS

Elastography has a fair specificity and sensitivity for diagnostic accuracy. Its major strength entails the detection of benignity, especially when only completely soft nodules are qualified as benign. The outcomes of our analysis show that FNA could safely be omitted in patients referred for analysis of their thyroid nodule when elastography shows it to be completely soft (Asteria elastography 1). This could prevent unnecessary invasive diagnostic procedures in a substantial portion of patients.

Strain US Elastography for the Characterization of Thyroid Nodules: Advantages and Limitation

Thyroid nodules, with their high prevalence in the general population, represent a diagnostic challenge for clinicians. Ultrasound (US), although absolutely reliable in detecting thyroid nodules, is still not accurate enough to differentiate them into benign and malignant. A promising novel modality, US elastography, has been introduced in order to further increase US accuracy. The purpose of this review article is to assess the thyroid application of US strain elastography, also known as real-time elastography or quasistatic elastography. We provide a presentation of the technique, and of up-to-date literature, analyzing the most prominent results reported for thyroid nodules differentiation. The practical advantages and limitations of strain elastography are extensively discussed herein.

Combined value of Virtual Touch tissue quantification and conventional sonographic features for differentiating benign and malignant thyroid nodules smaller than 10 mm

OBJECTIVES

This study aimed to investigate the value of sonographic features including Virtual Touch tissue quantification (VTQ; Siemens Medical Solutions, Mountain View, CA) for differentiating benign and malignant thyroid nodules smaller than 10 mm.

METHODS

Seventy-one thyroid nodules smaller than 10 mm with pathologic diagnoses were included in this study. The conventional sonographic features and quantitative elasticity features (VTQ) were observed and compared between benign and malignant nodules.

RESULTS

There were 39 benign and 32 malignant nodules according to histopathologic examination. When compared with benign nodules, malignant nodules were more frequently taller than wide, poorly defined, and markedly hypoechoic (P < .05). Color Doppler sonographic features were not significantly different between benign and malignant nodules. The VTQ value for malignant nodules (mean ± SD 3.260 ± 0.725 m/s) was significantly higher than that of benign ones (2.108 ± 0.455 m/s; P < .001). The cutoff point for the differential diagnosis was 2.910 m/s, with sensitivity, specificity, a positive predictive value, a negative predictive value, and diagnostic accuracy of 71.9%, 100%, 100%, 81.2%, and 87.3% respectively. Logistic regression analysis showed that a taller-than-wide shape, a poorly defined boundary, marked hypoechogenicity, and a VTQ value greater than 2.910 m/s were independent risk factors for malignancy, with odds ratios of 69.366, 41.864, 5.945, and 64.991. The combination of VTQ with a taller-than-wide shape had the highest sensitivity and specificity of 90.6% and 97.4%.

CONCLUSIONS

The shape, margin, echogenicity, and VTQ value are useful sonographic criteria for differentiating benign and malignant thyroid nodules smaller than 10 mm. When VTQ was combined with B-mode sonographic features, the sensitivity was improved significantly.

The use of ultrasound elastography in the assessment of malignancy risk in thyroid nodules and multinodular goitres

OBJECTIVE

The objective of our work is to use a surgical series to analyse the validity of elastography in evaluating the malignancy of thyroid nodules and multinodular goitres.

PATIENTS AND METHODS

The study examined 156 patients, 134 women (85·9%) and 22 men (14·1%), who underwent surgery for nodular thyroid disease between October 2008, and November 2010. The average age of the patients was 52 years (±14·42). Thirty-six patients (23·1%) presented with a single nodule, and 120 (76·9%) exhibited multinodular goitres. Prior to surgical intervention, all patients underwent colour eco-elastography using a qualitative five-point ordinal scale for nodule classifications. Test results were analysed using a receiver operating characteristic (ROC) curve, and an anatomical pathologic examination of surgical specimens was used as a gold standard diagnostic tool for comparison.

RESULTS

Of the 192 nodules analysed, 28 (14·6%) were malignant. Using elastography data, an ROC curve was obtained with an area under the curve of 0·662 (±0·060) and a 95% confidence interval (CI 95%) between 0·545 and 0·779 (P = 0·006). By establishing a cut-off point that classified thyroid nodules with an elastographic value greater than or equal to 3 as malignant, we achieved a sensitivity of 75%, specificity of 45·73%, positive predictive value of 19·1% and negative predictive value of 91%. The positive and negative likelihood ratios were 1·38 and 0·55, respectively.

CONCLUSIONS

Ultrasound elastography can provide information regarding malignancy risk in thyroid nodules and multinodular goitres. However, the sensitivity and specificity values obtained in our study are below those reported by other groups, a finding that calls into question the current clinical utility of ultrasound elastography.

Ultrasound elastography in the head and neck. Part II. Accuracy for malignancy

Ultrasound elastography (USE) describes a variety of ultrasound-based imaging techniques that measure tissue stiffness properties, and is currently under intense investigation for tissue characterization in several anatomic sites. This article summarizes the evidence regarding the accuracy of USE for malignancy in the head and neck. Currently, most published data pertains to small pilot studies with varied methodologies. Encouragingly, most studies have documented promising results for USE in terms of high accuracy for malignancy in thyroid nodules and cervical lymph nodes, which have surpassed conventional sonographic criteria. However, a minority of studies have documented opposite findings. USE seems to be suboptimal for salivary malignancies, and some evidence suggests that USE does not provide useful diagnostic information compared with conventional ultrasonography for miscellaneous neck masses. Further larger studies are required to validate these findings although, in view of the predominance of highly optimistic results for thyroid nodules and cervical lymph nodes, USE may become a useful ancillary technique in the routine diagnostic work-up of lesions in these tissues in the near future.

Application of Real-time Ultrasound Elastography in Diagnosing Benign and Malignant Thyroid Solid Nodules

Objective

Real-time ultrasound elastography (US-E) is a helpful tool in diagnosing thyroid nodules. This study aims to evaluate thyroid solid nodules, to establish the accuracy of US-E in providing information on the nature of these nodules, and to assess the clinical value of elasticity scores (ES) and strain ratio (SR) in differentiating thyroid solid nodules and to explore its distribution characteristics using pathological analysis as reference.

Methods

Traditional ultrasonography and US-E were performed on 131 thyroid solid nodules (99 benign ones and 32 malignant ones) in 120 patients (78 females and 41 males). Three radiologists evaluated the nodules based on a four-degree elasticity scoring system. The nodules were classified according to the ES as soft (ES 1-2) or hard (ES 3-4). The SR was calculated online.

Results

The sensitivity and specificity of the ES for thyroid cancer diagnosis were 78% and 80%, respectively. SR values ≥ 2.9 used as a standard to distinguish benign from malignant nodules had a sensitivity of 87% and a specificity of 92%. The SR of the benign lesions was 1.64±1.37, which was significantly different from that of malignant lesions, which was 4.96±2.13 (P<0.01).

Conclusions

Both the ES and SR were higher in malignant nodules than those in benign ones. Real-time US-E was a useful index in the differential diagnosis of thyroid solid nodules. It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence.

Diagnostic performance of combined elastosonography scoring and high-resolution ultrasonography for the differentiation of benign and malignant thyroid nodules

AIM

To evaluate the diagnostic performance of the combined use of elstosonography (USE) scoring and high-resolution ultrasonography (HRUS) for the differentiation of benign and malignant thyroid nodule.

PATIENTS AND METHODS

Forty-seven consecutive patients with 66 thyroid nodules were enrolled in the present study. Thyroid surgery had been already planned for all the patients. All of them were submitted to high-resolution ultrasonography and elastography scoring at the same sitting. The latter was determined with 5-point scoring method. The examination results were compared against pathological findings as the gold standard of reference.

RESULTS

The sensitivity, specificity, accuracy, positive predictive, and negative predictive values of HRUS in the differential diagnosis of thyroid nodules were 92.0%, 72.9%, 60.1%, 95.0%, and 63.1%, respectively, while that of ultrasound elastography scoring were 75.4%, 85.5%, 86.7%, 71.4%, and 90.5%, respectively. Combined use of both US techniques resulted in a higher diagnostic performance as it showed 95.4%, 94.8%, 95.2%, 82.3% and 98.8% sensitivity, specificity, accuracy, positive predictive, and negative predictive values, respectively.

CONCLUSIONS

The use of combined USE and HRS for the differentiation of benign and malignant thyroid nodules resulted in a high diagnostic performance and a significant statistical difference as compared to HRUS or USE alone (P=0.003).

Ultrasound sensitivity for thyroid malignancy is increased by real-time elastography: a prospective multicenter study

CONTEXT

Thyroid nodules are selected for biopsy on the basis of clinical and ultrasound (US) findings. Ultrasonography detects nodules at risk of malignancy, but its diagnostic accuracy does not rule out with certainty the possibility of cancer in lesions without suspicious findings.

OBJECTIVE

The objective of the study was to evaluate the diagnostic accuracy of real-time elastography (RTE) in thyroid nodules and to assess the improvement provided by combination of RTE, B-mode US, and color flow Doppler (CFD).

DESIGN

This was a prospective multicenter study.

PATIENTS

A consecutive series of 498 thyroid nodules was blindly evaluated by US, CFD, and RTE before biopsy or surgery. Nodules were classified at RTE by four-class color scale. Patients with benign cytology underwent follow-up over 12 months, whereas patients with indeterminate, suspicious, or malignant cytology were surgically treated.

RESULTS

At follow-up, 126 nodules were malignant and 372 benign. RTE classes III-IV showed 81% sensitivity and 62% specificity. The presence of at least one US risk factor (hypoechogenicity, microcalcifications, irregular margins, intranodular vascularization, and taller than wide shape) had 85% sensitivity and 91% negative predictive value. When RTE was combined with US, the presence of at least one of the six parameters had 97% sensitivity and 97% negative predictive value, with an odds ratio of 15.8 (95% confidence interval 5.7-43.8).

CONCLUSIONS

RTE is a valuable tool for detecting malignant thyroid lesions with a sensitivity similar to traditional US and CFD features. By adding RTE evaluation, the sensitivity for malignancy of US findings is markedly increased and the selection of nodules that do not need cytology is made more reliable.

Real-time elastography: a useful tool for predicting malignancy in thyroid nodules with nondiagnostic cytologic findings

OBJECTIVES

The aim of this study was to evaluate the predictive value of sonography and sonographic elastography in thyroid nodules with nondiagnostic cytologic findings.

METHODS

The study included 101 patients (74 female, mean age ± SD, 55 ± 11 years [range, 27-70 years]; and 27 male, mean age, 62 ± 9 years [range, 42-72 years]) who had at least 1 nodule with nondiagnostic cytologic findings at two different fine-needle aspiration cytologic evaluations and with an indication for hemi or total thyroidectomy for clinical suspicion of malignancy, nodule size, or the occurrence of a coexisting nodule with cytologic findings suspicious for malignancy. All of the patients underwent sonography and elastography 2 months after the second fine-needle aspiration and before surgery. The elastogram was matched with an elasticity color scale and classified as follows: score 1, nodules with high elasticity (soft); score 2, nodules with indeterminate elasticity; and score 3, nodules with low elasticity (hard).

RESULTS

A total of 135 nodules (93.7%) were hyperplastic; 15 (9.4%) were papillary carcinomas; and 9 (6.3%) were follicular adenomas. The association of scores 2 and 3 identified 12 of 15 thyroid cancers (sensitivity, 80.0%; specificity, 93.7%; positive predictive value, 57.1%; negative predictive value, 97.8%; and accuracy, 92.4%), whereas the association of conventional sonographic features plus scores 2 and 3 identified all of the cancers (specificity, 70.8%; positive predictive value, 26.3%; negative predictive value, 100%; and accuracy, 73.6%).

CONCLUSIONS

Our data suggest that elastography could be a promising tool in the management of nodules that are nondiagnostic at cytologic evaluation, reducing unnecessary surgery.

Ultrasound elastography is not superior to grayscale ultrasound in predicting malignancy in thyroid nodules

BACKGROUND

Several studies have evaluated the ability of ultrasound elastography (USE) to diagnose malignant nodules. However, these studies had important limiting factors, selection bias and small sample size. The aims of the present study were to prospectively assess, in a large group of patients, the diagnostic power of USE for detecting malignancy in thyroid nodules, and to compare this technique with B-mode grayscale ultrasonography (BUS) and power Doppler ultrasonography (PD).

METHOD

There were 194 patients with 237 thyroid nodules who were examined using BUS, PD, and USE. USE scores were classified according to the elasticity: score 1 as high, score 2 as intermediate, and score 3 as low (i.e., a high degree of stiffness). Fine-needle aspiration cytology (FNAC) was performed in all nodules at least two different times. Nodules having two benign FNAC readings that did not change the diameter during a 6-month follow-up period were classified as benign. Patients having thyroid nodules with indeterminate, suspicious, or malignant cytology had total or hemithyroidectomy to remove the nodule and treat the malignancy.

RESULTS

Fifty eight (25%) nodules in 45 (23%) patients were found to be malignant. USE had a limited sensitivity and a positive predictive value in detecting malignant thyroid nodules and was not superior to BUS. USE had almost the same specificity and a negative predictive value as BUS. A power Doppler type-3 pattern was not of sufficient sensitivity to detect malignancies in thyroid nodules.

CONCLUSIONS

In contrast to earlier reports, this current study noted a lower sensitivity and specificity of USE for the diagnosis of malignancy in thyroid nodules than previously reported.

Sonoelastographic qualitative analysis for management of salivary gland masses

OBJECTIVES

Our aim was to investigate whether the use of a qualitative elasticity scoring method by sonoelastography is beneficial for management of salivary gland masses.

METHODS

Thirty-six patients with salivary gland masses (30 parotid and 6 sub-mandibular) were prospectively included in this study. For each lesion, B-mode sonographic and sonoelastographic images were obtained. Elasticity scores were determined by a 4-point scoring method. Differences among scores for benign and malignant masses were assessed by the Mann-Whitney U test. Qualitative variables were compared by the Pearson χ² test. The findings were compared with histopathologic diagnoses.

RESULTS

The score values of 28 benign masses ranged from 1 to 4, whereas the values of 8 malignant masses ranged from 2 to 4. The mean scores ± SD were 2.25 ± 0.92 for benign lesions and 3.0 ± 0.75 for malignant lesions (P < .05). When we considered scores 1 and 2 as benign and scores 3 and 4 as malignant, 10 false-positive results were determined by the 4-point scoring method, and 64.2% of benign masses were diagnosed.

CONCLUSIONS

Sonoelastography might be regarded as another sonographic parameter for management of salivary gland masses in terms of detecting benign masses.

Shear wave elastography of thyroid nodules in routine clinical practice: preliminary observations and utility for detecting malignancy

OBJECTIVE

To evaluate real-time shear wave ultrasound elastography (SWE) for characterizing focal thyroid lesions in routine clinical practice.

METHODS

Seventy-four patients with 81 focal thyroid lesions undergoing conventional US with needle cytology also underwent SWE. Absolute and relative SWE stiffness measurements on colour-coded elastograms were correlated with cytology and their discriminatory performances assessed.

RESULTS

Seventeen nodules were malignant (13 papillary, 4 other cancers), 45 benign (43 hyperplastic nodules, 2 focal thyroiditis), 5 indeterminate ("follicular lesions"), and 5 had inadequate cytology. SWE results were higher in malignant than benign nodules (P values 0.02-0.05) although their discriminatory performances were mediocre (AUCs 0.58-0.74). The most accurate SWE cut-off, 34.5 kPa for a 2-mm region of interest, achieved 76.9 % sensitivity and 71.1 % specificity for discriminating papillary cancer from benign nodules. No thresholds produced high sensitivity without lowering specificity appreciably, and vice versa. Nodule size correlated with SWE for benign nodules (P < 0.01). Intranodular cystic change or calcification did not influence SWE. Qualitatively, elastographic artefacts and foci lacking colour elasticity signal occurred in some solid nodules.

CONCLUSION

Although malignant nodules are generally stiffer than benign nodules, the precision results do not suggest a definitive role for SWE, at present, in identifying or excluding thyroid malignancy.

KEY POINTS

• Shear wave ultrasound elastography (SWE) offers new insight into thyroid disease. • Papillary cancers have higher SWE indices (equating to higher stiffness) than benign nodules. • SWE appears limited in terms of identifying or excluding thyroid malignancy accurately. • Vertically aligned elastographic artefacts can occur in thyroid SWE. • Areas lacking SWE colour signal can occur in some solid thyroid nodules.

Clinical importance of diastolic sonoelastographic scoring in the management of thyroid nodules

We determined that the application of a 5-point scoring method by using an external manual compression method synchronized with the diastolic period of the carotid artery by sonoelastography was helpful in the management of thyroid nodules. The mean scores on sonoelastography were 2.74 ± 0.97 for 62 benign nodules and 3.90 ± 0.88 for 10 malignant nodules (P < .01). Eighty-seven percent of benign nodules were determined when a cutoff point between scores 3 and 4 was used.

Guidelines of the French society of endocrinology for the management of thyroid nodules

The present document is a follow-up of the clinical practice guidelines of the French Society of Endocrinology, which were established for the use of its members and made available to scientific communities and physicians. Based on a critical analysis of data from the literature, consensuses and guidelines that have already been published internationally, it constitutes an update of the report on the diagnostic management of thyroid nodules that was proposed in France, in 1995, under the auspices of the French National Agency for Medical Evaluation (l'Agence nationale d'évaluation médicale). The current guidelines were deliberated beforehand by a number of physicians that are recognised for their expertise on the subject, coming from the specialities of endocrinology (the French Thyroid Research Group) and surgery (the French Association for Endocrine Surgery), as well as representatives from the fields of biology, ultrasonography, cytology and nuclear medicine. The guidelines were presented and submitted for the opinion of the members of the Society at its annual conference, which was held in Nice from 7-10 October 2009. The amended document was posted on the website of the Society and benefited from additional remarks of its members. The final version that is presented here was not subjected to methodological validation. It does not claim to be universal in its scope and will need to be revised in concert with progress made in technical and developmental concepts. It constitutes a document that the Society deems useful for distribution concerning the management of thyroid nodules, which is current, efficient and cost effective.

Good practice guide for cervical ultrasound scan and echo-guided techniques in treating differentiated thyroid cancer of vesicular origin

Good practice guide for cervical ultrasound scan and echo-guided techniques in treating differentiated thyroid cancer of vesicular origin. American, European and French Recommendations for the treatment of differentiated vesicular thyroid cancer were recently published. Cervical ultrasound scanning is now considered a key examination in the follow-up of these cancers. This examination is noninvasive, easy to perform and to obtain, is not costly, but remains operator-dependent. To date, there are no recommendations published that assemble all the technical aspects, results, indications and the limits of this examination in the initial medical report and the follow-up of these cancers. In order to standardise the procedure and validate the quality of the examination, a workgroup made up of a panel of experts particularly involved in carrying out ultrasound scans was set up. The aim was to draw up a good practice guide for performing cervical ultrasound scans and echo-guided techniques in treating patients with differentiated thyroid cancer of vesicular origin. The main objectives are to: (a) standardise the procedure and reports, (b) define the criteria for establishing whether lesions identified during a cervical ultrasound scan are malignant or benign, (c) standardise the indications for carrying out cytological tests and an in situ assay of markers, (d) help doctors to select the patients who ought to receive a cervical ultrasound scan and or cytological tests, (e) discuss how frequently the examinations should be carried out depending on the risk of recurrence.

Diagnostic value of elastosonographically determined strain index in the differential diagnosis of benign and malignant thyroid nodules

Elastosonography (ES) is a newly developed method that is used for the differential diagnosis of benign and malignant thyroid nodules. In different studies, ES scoring has been compared with histopathological findings, and sensitivity and specificity of the scoring were calculated. In this study, it determines the strain index (SI) as well as the ES to score thyroid nodules, and establishes the role for these parameters in the differential diagnosis of thyroid nodules using histopathological analysis as a reference standard. Real-time ES in transverse axis (TA) and longitudinal axis (LA) was performed in 391 nodules of 292 patients. ES scoring was made for all the nodules. SI in TA and LA was calculated for four times in each nodule and mean values were determined. The results were compared with final histopathological diagnoses. In histopathological examinations, 125 (31.97%) of 391 nodules were malignant and 266 (68.03%) were benign. Of these histopathologically benign nodules, 189 (%71.05) were also probably benign according to elastosonographic scoring (scores of 1, 2, or 3), while 77 (28.95%) were probably malignant (scores of 4 or 5). Among 125 histopathologically malignant nodules, 52 (41.60%) were probably benign and 73 (58.40%) were probably malignant according to elastosonographic scoring. There was a significant relation between scoring and histopathological findings (χ(2) = 36.513; P < 0.001). Accordingly, sensitivity and specificity of ES scoring were 58.4 and 71.0%, respectively. ROC analysis value obtained for strain ratios in LA (AUC: 75.5%; P < 0.001) had a higher significance compared to ROC analysis value obtained for strain ratios in TA (AUC: 66.0%). Thus, ROC analysis evaluation was applied only for SI in LA. The optimal SI cut-off value in LA for all the nodules was found to be 16.709 (sensitivity: 73.4%, specificity: 70.0%) (AUC: 75.4 ± 0.03%; 70.2-80.5%). SI cut-off value corresponding to 90% sensitivity in this axis was 4.516 (specificity: 35.7%). Sensitivity and specificity of SI values that were determined according to morphological features of nodules in gray-scale ultrasonography were higher. For hypoechoic nodules with microcalcifications and without a halo, SI cut-off value, sensitivity, and specificity were 17.020, 84.3, and 81.1%, respectively. Our study is the first clinical-wide series study that measured, used, and compared the ES scoring and SI cut-off values for the differential diagnosis of benign and malignant thyroid nodules. This study indicates that measurement of SI with ES as a noninvasive procedure may be used as an adjunctive method to the conventional methods for the differential diagnosis of thyroid nodules.

Elastosonography: a possible new tool for diagnosis of adenomyosis?

OBJECTIVES

Adenomyosis is a disorder defined by the presence of ectopic endometrial glands and stroma within the myometrium. Transvaginal ultrasound (TVU) is currently the first-line examination for this condition and the aim of this paper is to relate a pilot experience that was conducted using TVU to evaluate adenomyosis and which started from the assumption that tissues with anatomopathological differences show different elasticity values.

METHODS

Using standard B-mode analysis and elastosonography, we evaluated 30 consecutive women with suspected uterine adenomyosis. In 15 cases the diagnosis was confirmed by histology.

RESULTS

The adenomyotic area presented more softness (red and green) compared with the surrounding uterine tissue (blue); the borders of the adenomyotic area corresponded to the borders of the green area.

CONCLUSIONS

These preliminary results suggest that elastosonography could be considered a useful tool in the diagnosis of adenomyosis because it is non-invasive, easy to understand, easy to perform, and has a short learning curve towards becoming skilled at the procedure.

Real-time elastosonography: useful tool for refining the presurgical diagnosis in thyroid nodules with indeterminate or nondiagnostic cytology

BACKGROUND

Indeterminate and nondiagnostic patterns represent the main limitation of fine-needle aspiration (FNA) cytology of thyroid nodules, clinical and echographic features being poorly predictive of malignancy. The newly developed real-time ultrasound elastography (USE) has been previously applied to differentiate malignant from benign lesions. The aim of this study was to get further insights into the role of USE in the presurgical diagnosis of nodules with indeterminate or nondiagnostic cytology.

PATIENTS

The study included 176 patients who had one (n=138) or multiple (n=38) nodules with indeterminate or nondiagnostic cytology on FNA, for whom histology was available after thyroidectomy. A total of 195 nodules (142 indeterminate, 53 nondiagnostic) were submitted to USE, and elasticity was scored as 1 (high), 2 (intermediate), or 3 (low).

RESULTS

In indeterminate lesions, the score 1, describing high elasticity, was strongly predictive of benignity, being found in 102 of 111 benign nodules and in only one of 31 carcinomas (P<0.0001). By combining the scores 2 and 3, USE had a sensitivity of 96.8% and a specificity of 91.8%. In nodules with nondiagnostic cytology, score 1 was found in 39 of 45 benign nodules and in only one of eight carcinomas (P<0.0001). By combining the scores 2 and 3, USE had a sensitivity of 87.5% and a specificity of 86.7%.

CONCLUSIONS

USE may represent an important tool for the diagnosis of thyroid cancer in nodules with indeterminate or nondiagnostic cytology and may prove useful in selecting patients who are candidates for surgery.

Thyroid nodules in acromegaly: The role of elastography

INTRODUCTION

Ultrasound elastography (US-E) is a helpful tool for the diagnosis of thyroid cancer. In acromegaly, multinodular goiter is a common occurrence while the prevalence of thyroid cancer is still matter of debate. Our aims were to evaluate thyroid nodules in acromegaly and to assess the accuracy of US-E in providing information on their nature (benign vs. malignant) using cytological analysis as a reference.

MATERIALS AND METHODS

US-E was performed in 25 patients with acromegaly (active in 10 cases, medically controlled in 8, and cured by pituitary surgery in 7), each of whom had at least one solid thyroid nodule. A total of 90 nodules were classified according to the elastography scores (ES): ES1 and ES2 for soft nodules, ES3 and ES4 for an elastic lesions. FNAC was performed in 78.6% of the ES 4 lesions and 54.1% of the ES 3 nodules.

RESULTS

Fourteen of the 90 nodules (15.5%) displayed an ES of 1, 25 (27.7%) an ES of 2, 37 (41.3%) an ES of 3, and 14 (15.5%) an ES of 4. The prevalence of hard nodules in patients with active acromegaly (68.9%) was greater than that observed in patients with cured (44.4%) or controlled (52.5%) acromegaly. The prevalence of hard nodules in the total series (56.7%) was higher than that reported in nonacromegalic goitrous subjects. All thyroid nodules subjected to FNAC were negative for malignant cells and follicular lesions.

DISCUSSION

Acromegaly (particularly active forms) is associated with a high prevalence of stiff thyroid nodules that exceeds that observed in nonacromegalic patients with goiters (33.7%). However, these nodules were never malignant at cytology, and their firmness is probably due to fibrosis. US-E therefore appears to be of limited value for the diagnosis of thyroid cancer in patients with acromegaly.

Real-time elastography for the differentiation of benign and malignant thyroid nodules: a meta-analysis

BACKGROUND

Work-up of thyroid nodules remains challenging. Fine-needle aspiration (FNA) has been shown to be the most cost-effective way to select patients for surgery with sensitivities of 54%–90% and specificities of 60%–96% for the detection of malignant lesions. Ultrasound-based real-time elastography (RTE) enables the determination of tissue elasticity and has shown promising results for the differentiation of thyroid nodules. A meta-analysis was performed to assess the overall performance of RTE for the differentiation of thyroid nodules.

METHODS

Literature databases were searched. The inclusion criteria for studies were the use of FNA cytology histopathology of surgical specimens as the diagnostic reference standard and assessment of sensitivity and specificity of RTE. The meta-analysis was performed using an inverse variance method and the Der Simonian and Laird Random effect estimator in case of established heterogeneity.

RESULTS

Eight studies that included a total of 639 thyroid nodules were analyzed. The overall mean sensitivity and specificity for the diagnosis of malignant thyroid nodules by RTE of the eight studies was 92% confidence interval 88–96 and 90% confidence interval 85–95, respectively. A significant heterogeneity was found for specificity of the different studies.

CONCLUSIONS

RTE has a high sensitivity and specificity in the evaluation of thyroid nodules. This technique might be useful in conjunction or even instead of FNA to select patients with thyroid nodules for surgery.

Utility of the ultrasound elastographic systolic thyroid stiffness index in reducing fine-needle aspirations

OBJECTIVE

The purpose of this study was to evaluate whether ultrasound elastography performed by using carotid pulsation as a compression source and generating the systolic thyroid stiffness index (STSI) can be used as a pre-fine-needle aspiration (FNA) screening tool.

METHODS

Ultrasound data previously acquired from 62 thyroid nodules in 59 patients who underwent a thyroid FNA were used. Pulsation from the carotid artery was used as the compression source, and the strain was calculated offline. A metric called the STSI was computed for each nodule during systole. On the basis of the derived STSI value, thyroid nodules were retrospectively classified into 2 types: I, no FNA (observation only); and II, FNA.

RESULTS

The STSI value of malignant nodules (n = 12) was significantly higher than that of benign nodules (n = 39; P < .00002). Using an STSI cutoff value of 10, 31 nodules were classified as type I, all of which were benign, whereas 20 nodules were classified as type II, 12 malignant and 8 benign, with sensitivity of 100% and specificity of 79.4%. This suggests that ultrasound elastography could have screened out 31 type I nodules, reducing the number of FNAs by 60.8%.

CONCLUSIONS

Thyroid ultrasound elastography has the potential to substantially reduce the number of FNA biopsies by detecting type I benign nodules. Patients with suspicious type II nodules would be referred for an FNA. Future prospective studies are needed to confirm the efficacy of thyroid ultrasound elastography as a triage tool to FNA.

Role of thyroid ultrasound in the diagnostic evaluation of thyroid nodules

Thyroid ultrasound (US) features associated with malignancy in thyroid nodules are microcalcifications, hypoechogenicity, irregular margins or absent halo sign, solid aspect, intranodular vascularization, and shape (taller than wide).These patterns, taken singly, are poorly predictive. When they are simultaneously present the specificity increases at the expense of sensitivity. US elastography (USE) is a powerful new diagnostic tool that assesses hardness as an indicator of malignancy in thyroid nodules. USE has high specificity and sensitivity independent of the nodule size, and this predictive value is maintained in follicular lesions. Available data suggest that USE is the best available non-invasive tool comparable to fine-needle aspiration (FNA) for the evaluation of thyroid nodules, provided that the nodule is solid and devoid of coarse calcifications. Thus, conventional US retains its importance for selecting nodules in which USE is predictive. In conclusion, USE has great potential as a new tool for the diagnosis of thyroid cancer, especially in nodules with indeterminate cytology.