Shear wave elastography versus real-time elastography on evaluation thyroid nodules: A preliminary study

Objective

To comparatively evaluate shear wave elastography (SWE) and real-time elastography (RTE) in distinguishing malignant from benign thyroid nodules.

Methods

49 patients with 64 focal thyroid nodules were enrolled and underwent SWE and RTE before surgery. SWE elasticity indices (mean, minimum and maximum value of 2-mm region of interest) of nodules were measured. For RTE, elastograms were assessed by Rago criteria and nodules with scores of 4 or 5 were classified as suspicious for malignancy. Surgery histopathologic results were adopted as diagnostic standard.

Results

Of the 64 nodules, 19 were papillary thyroid carcinomas and 45 were benign. SWE indices were significantly higher in malignant than benign nodules (P < 0.05). Areas under the ROC curves (AUC) of SWE parameters were 0.840, 0.831 and 0.788, which were not significantly different from that of RTE showed as 0.880 (P = 0.148–0.482). When the most accurate cut-off, 38.3 kPa for mean value was applied to predict malignancy, the diagnostic specificity, sensitivity, accuracy, positive predictive value and negative predictive value of SWE and RTE were 68.4% versus 79.0%, 86.7% versus 84.4%, 81.3% versus 78.1%, 68.4% versus 64.7% and 86.7% versus 83.3%, respectively (P = 0.683–1.000).

Conclusion

SWE as a promising tool can be performed in differentiating thyroid nodules with comparable results to RTE.     

Qualitative and quantitative evaluation of solitary thyroid nodules with contrast-enhanced ultrasound: initial results

To assess the feasibility of contrast-enhanced ultrasound (CEUS) of the thyroid gland and to evaluate the potential of this method for characterising solitary thyroid nodules.18 patients affected by solitary thyroid nodules (size range: 0.6 to 3.6 cm; mean: 1.8 cm) confirmed by surgery (nine papillary carcinomas, four follicular carcinomas, three hyperplasias, one follicular adenoma and one Plummer’s adenoma) underwent pulse inversion US at low M.I. (0.06 to 0.08) after i.v. injection of a 2.4-mL bolus of SonoVue. Baseline echogenicity and the dynamic enhancement pattern of each nodule, in comparison with adjacent thyroid parenchyma, were assessed. Signal intensity values on grey-scale images were also calculated at baseline, 30 s, 60 s and 120 s after SonoVue administration. Following administration of SonoVue, malignant nodules showed absent (4 out of 13), faint dotted (4 out of 13) and diffuse (5 out of 13) contrast enhancement, in this last case inhomogeneous (4 out of 5 cases) or homogeneous (1 out of 5). Benign nodules showed diffuse contrast enhancement, both homogeneous (3 out of 5) and heterogeneous (2 out of 5). Quantitative data have confirmed subjective findings, but CEUS never modified precontrast analysis. CEUS of thyroid gland is a feasible technique, but overlapping findings seem to limit the potential of this technique in the characterization of thyroid nodules.     

Comparison analysis between conventional ultrasonography and ultrasound elastography of thyroid nodules

Objective

To compare the effectiveness of conventional ultrasonography and ultrasound elastography in differential diagnosis of thyroid nodular diseases.

Methods

244 patients with 291 thyroid nodules were examined by ultrasonography and ultrasound elastography respectively; the examination results were compared against pathological findings to determine the effectiveness of these two examination methods.

Results

The sensitivity and positive predictive value of conventional ultrasonography is higher than those of ultrasound elastography, but its specificity, accuracy, and negative predictive value is lower than those of the later.

Conclusions

Ultrasound elastography is superior to conventional ultrasonography in differential diagnosis of thyroid nodules. However, ultrasonography is the basis of examination; only on this basis, an additional ultrasound elastography examination could greatly improve the diagnostic rate of thyroid nodular diseases.     

微创介入治疗在甲状腺良恶性结节的应用进展

随着现代超声技术的不断发展,超声引导下微创介入治疗以创伤小、定位精确、疗效好等优点,已广泛应用于临床治疗。常见的介入治疗方法包括:超声引导下经皮酒精消融(PEI)、激光消融(LA)、微波消融(MWA)、射频消融(RFA)、高强度聚焦超声消融(HIFU)。本文就甲状腺结节的超声引导介入治疗的适应证及禁忌证、原理、疗效以及并发症的研究进展进行综述。     

How to combine ultrasound and cytological information in decision making about thyroid nodules

The purpose of this study was to evaluate the role of sonographic-cytological correlation in determining which nodules should be reaspirated to reduce the false-negative rate of fine-needle aspiration biopsy (FNAB). A retrospective cohort study was performed on a database of 568 patients with 672 focal thyroid nodules. An independent two-sample t-test was used to compare the risk of malignancy according to clinical factors. We evaluated the risk stratification of malignancy according to US groupings and cytological results. Additionally, we calculated the false-negative rate of FNAB and investigated the cytological results of repeat aspiration. The malignancy rate (92.2–98.5%) was high in thyroid nodules designated “malignant” or “suspicious for papillary carcinoma” on FNAB, regardless of US features. In contrast, when focal thyroid nodules had “benign” readings on FNAB, the malignancy rate was lower for the “probably benign” US features (2.9%) than for the suspicious nodules (56.6%). The false-negative rate of FNAB was 5.8%. Repeat aspiration revealed “suspicious for malignancy” or “malignancy” results in 15 (93.8%) of 16 thyroid cancers with “benign” results on initial aspirate. This study demonstrated repeat FNAB should be performed on focal thyroid nodules with suspicious US features even when initial FNAB results are benign.     

超声造影不同增强模式对良恶性甲状腺结节的鉴别价值

目的:探讨甲状腺良恶性结节实时灰阶超声造影的增强表现及其鉴别诊断价值.方法:46例甲状腺病变患者先行常规二维超声及彩色多普勒检查后,再行超声造影检查,观察甲状腺结节的增强模式,将其分为不均匀强化、均匀强化、环形强化及不强化;同时观察甲状腺结节造影前后测值的变化.结果:46例患者共49个甲状腺结节(23个恶性结节、26个...     

The value of strain ratio in differential diagnosis of thyroid solid nodules

Objective

To assess the clinical value of strain ratio in differentiating thyroid solid nodules and explore its distribution characters based on pathological results.

Materials and methods

The study was approved by the ethic committee and the informed consents were signed. Ninety nine solid thyroid nodules (67 benign and 32 malignant) from 71 female (mean age 46.3 ± 9.8 years) and 28 male (mean age 54.9 ± 11.7 years) patients were evaluated. Five radiologists evaluated the nodules based on a four-degree elastography score system. Strain ratio was calculated on-line. Diagnostic performances of the two evaluations were compared using Receiver Operating Characteristic (ROC) curves. Values of different pathological nodules were compared by one-way ANOVA.

Results

Areas under the ROC curve (AUC) of the five readers were 0.82, 0.81, 0.79, 0.73 and 0.83, respectively. The AUC of strain ratio evaluation was higher (0.88 vs. 0.79, p < 0.001) than that of the ES score evaluation. Best cut-off points of the two evaluations were 3.5 (82% sensitivity, 72% specificity) and 4.225 (81% sensitivity, 83% specificity), respectively. Both the ES score and strain ratio were higher for malignant nodules than that for benign ones (p < 0.001).

Conclusions

Strain ratio was a useful index in differential diagnosis of thyroid solid nodules. It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence. The best cut-off point for benign and malignant nodules was 4.2.     

The clinical value of ultrasound elastography in predicting malignant thyroid nodules

Objective

This study aims to evaluate the clinical value of ultrasound elastography (USE) in providing information on the nature of the thyroid nodules. This was performed using the elastography score and strain ratio in differentiating thyroid benign and malignant nodules and the histopathological examination was used as the diagnostic standard of reference.

Methods

We examined 84 thyroid nodules in 62 patients with ultrasound elastography. Elastography score was assigned based on a four-point scale according to the classification proposed by Itoh et al. with a score of 1 (low stiffness over the entire nodule) to a score of 4 (high stiffness over the entire nodule). Thyroid strain ratio (normal tissue to lesion strain ratio) was calculated. Histopathological results were the standard reference. The area under the curve (AUC) and the best cut-off point were both obtained using receiver-operating characteristic (ROC) curve analysis. The sensitivity, specificity, and accuracy of both techniques were calculated.

Results

Fifty-four of the 84 nodules had scores of 1 and 2, and 50 of these nodules were diagnosed histopathologically as benign. Thirty of the 84 nodules had a score of 3 and 4, and 21 of these nodules were diagnosed histopathologically as malignant. The scores of 1 and 2 with Itoh criteria were significantly seen in benign nodules, whereas, scores of 3 and 4 were significantly seen in malignant nodules (p < 0.05) with sensitivity 84%, specificity 84.7%, PPV 70%, NPV 92.6% and accuracy 84.5%. The mean SR for the benign nodules and malignant ones was significantly different (2.92 ± 0.96 vs. 4.53 ± 0.82, p < 0.001). With ROC analysis, the best cut-off strain ratio point was 3.5 for differentiating benign and malignant nodules with area under the curve (AUC) = 0.87 (0.8–0.95). The sensitivity of the strain ratio was 88%, while the specificity was 86.4%, PPV = 73.3%, NPV = 94.4% and accuracy = 86.9%.

Conclusions

Both the elastographic score and strain ratio are higher in malignant nodules than those in benign ones. Ultrasound elastography can provide quantitative information on thyroid nodule helping in differentiating benign and malignant ones.     

超声造影鉴别甲状腺良恶性结节的价值

目的应用超声造影观察甲状腺良恶性结节血流灌注特征,探讨超声造影鉴别甲状腺良恶性结节的价值。方法对28例患者28个甲状腺结节行超声造影检查,观察甲状腺结节超声造影增强特征,应用Qontraxt定量分析软件对甲状腺良恶性结节血流灌注特征进行时间-强度曲线分析。定量参数包括峰值强度(Peak)、达峰时间(TP)、曲线尖度(Sharpness)及曲线下面积(AUC)。结果①甲状腺良性结节造影后多边界清晰,形态规则,以低强化多见。②甲状腺恶性结节造影后多边界不清,形态欠规则,以等强化及低强化为主。③甲状腺良恶性结节的强化类型差异无统计学意义(P>0.05),具有一定的重叠性。环状强化更多出现在良性结节中。④甲状腺恶性结节达峰时间短于良性结节,曲线尖度、曲线下面积高于良性结节,差异有统计学意义(P<0.05)。结论甲状腺良、恶性结节的超声造影增强特征及时间-强度曲线存在一定的重叠性,但其与结节的病理生理密切相关,可以为甲状腺结节良恶性的鉴别提供有效的、补充性信息,有一定的诊断价值。     

细胞学穿刺未定性甲状腺结节的恶性预测因子探讨

目的：探讨细胞学未定性甲状腺结节的恶性预测因子。方法：回顾性搜集2009年-2013年88例细胞学检查未定性甲状腺结节患者的相关资料。对选定结节进行临床、实验室、MRI、超声和穿刺细胞学（Bethesda分类标准）多方面分析研究,多变量分析后建立预测模型。结果：88例中有25例甲状腺结节为恶性病变（28．41％,25／88）。对比分析良性结节组和恶性结节组,两组中患者的性别、血清FT4水平、有无甲状腺自身免疫性疾病、微钙化的MRI特征、结节中央血流丰富的us特征在两组间差异均无统计学意义（P〉0．05）。微钙化的us特征、边界模糊的MRI特征以及细胞学结果分类第Ⅳ类（Bethesda分类系统）在两组间差异有统计学意义（P〈O．05）。在多变量分析后,预测模型表明Bethesda分类Ⅳ类和微钙化的US特征以及边界模糊的MRI特征均可作为未定性甲状腺结节的恶性预测因子,符合率为88．6％。结论：研究证实Bethesda分类Ⅳ、微钙化的US特征、边界模糊的MRI特征均是未定性甲状腺结节的恶性预测因子。     

Prospective evaluation of multiparametric ultrasound and quantitative elastosonography in the differential diagnosis of benign and malignant thyroid nodules: preliminary experience

Purpose

To assess the clinical value of quantitative elastosonography compared with multiparametric ultrasound in differentiating the nature of thyroid nodules.

Methods and materials

Ninety-seven consecutive patients (32 males, 65 females, mean age, 54 years, range 20–81 years) with thyroid nodules previously detected at color-Doppler ultrasound (CDUS), were prospectively examined with elastosonography with dedicated quantitative software (Elasto-Q, Toshiba) before surgery. Ultrasound examination and elastosonography were evaluated by two investigators in consensus. US features, color-Doppler pattern, and strain ratio value were evaluated. Sensitivity and specificity of CDUS and sono-elastography were compared using X² test and ROC curves.

Results

Sensitivity and specificity of hypoechogenicity, irregular margins or suspicious halo features, CDUS blood flow pattern, and strain ratio in the diagnosis of malignant nodules were 56.8%, 62.2%, 54.1% and 97.3% and 71.7%, 93.3%, 28.3%, and 91.7%, respectively. Elastosonography was more sensitive and specific than all ultrasonographic features in predicting malignancy of the thyroid nodules (p < 0.0001). According to elastosonographic features the lesions characterized by strain ratio ≥2 were highly likely to be of malignant nature (p < 0.0001, O.R. 396, 95%, CI: 44–3530).

Conclusions

The results of the present study suggest that elastosonography with Q system is a valuable tool in the characterization of thyroid nodules and it seems to be far more accurate than CDUS. These findings as well as those of previous studies support its use in selecting patients who are candidates for surgery.     

灰阶超声结合超声弹性成像改良评分法在甲状腺实性结节中的应用

目的:探讨超声弹性成像改良评分法在诊断甲状腺结节良恶性中的价值。方法:对45例共71个实性结节进行弹性成像,按新评分法分为五级,并与病理结果进行相关分析。结果:灰阶超声诊断甲状腺疾病良恶性的敏感性、特异性、准确性分别是81%、94%、90.1%;新评分法诊断甲状腺疾病良恶性的敏感性、特异性、准确性分别是85.7%、96%、93%;二者联合使用敏感性、特异性、准确性分别是85.7%、98%、94.4%结论:改良评分法简便、准确、易于操作,与灰阶超声结合有助于提高对甲状腺疾病的诊断。     

甲状腺结节钙化在超声诊断甲状腺癌中的价值

目的：探讨超声检查甲状腺结节钙化在诊断甲状腺癌的应用价值。方法：对452例术前超声诊断甲状腺结节患者的临床资料进行分析。结果：452例甲状腺结节患者,甲状腺癌的钙化率62.5%与良性病变的钙化率19.3%比较,P〈0.01;甲状腺癌微小钙化占钙化总数的70%,良性结节微小钙化占钙化总数的38.5%,两者之间存在明显差异,P〈0.01。结论：超声探测甲状腺结节钙化对诊断甲状腺癌有重要指导意义,微小钙化是甲状腺癌的特征性诊断。特别是对乳头状癌。     

Role of ultrasound,color doppler,elastography and micropure imaging in differentiation between benign and malignant thyroid nodules

Purpose

To evaluate the role of ultrasound elastography, Doppler and micropure imaging in the assessment of thyroid nodules, using the pathological analysis as the reference standard.

ACR TI-RADS分类联合剪切波弹性成像对甲状腺结节的诊断价值

目的探讨美国放射学会(ACR)甲状腺影像报告与数据系统(TI-RADS)联合剪切波弹性成像(SWE)对甲状腺结节的诊断价值。方法回顾性分析167例患者的甲状腺结节(共243个)的ACRTI-RADS分类和SWE图像特征,以手术病理结果为金标准,绘制受试者工作特征(ROC)曲线,得出SWE诊断甲状腺结节良恶性的最佳阈值。分析ACRTI-RADS分类、SWE以及两者联合应用对甲状腺结节良恶性诊断的结果,绘制ROC曲线,将三种方法的诊断结果与病理结果进行一致性分析。结果243个甲状腺结节中,病理诊断恶性结节183个,良性结节60个。当选择最佳阈值SWE_max=38.6kPa,SWE_mean=27.5kPa时,两种方法联合诊断甲状腺结节良恶性的敏感性、特异性为96.72%、88.33%,曲线下面积(0.925)明显大于ACRTI-RADS分类(0.793)或SWE(0.843)单独诊断,差异有统计学意义(P<0.01)。结论ACRTI-RADS分类联合SWE应用可进一步提高甲状腺结节的诊断水平。     

Diagnostic value of sonography, ultrasound-guided fine-needle aspiration cytology, and diffusion-weighted MRI in the characterization of cold thyroid nodules

Introduction

The purpose of this prospective study was to assess the diagnostic value of different modalities for the characterization of cold thyroid nodules.

Methods

In 35 patients with cold nodules, thyroid carcinoma was suspected on scintigraphy. These patients were prospectively investigated with sonography, ultrasound-guided fine-needle aspiration (USgFNA), and quantitative diffusion-weighted imaging magnetic resonance imaging (DWI) (navigated echo-planar imaging; maximum b-value 800 s/mm²) prior to surgery. The sonographic findings, USgFNA cytology, and the apparent diffusion coefficient (ADC) values of DWI were correlated with the postoperative histology of benign and malignant lesions. Statistical analysis was performed with the Kruskal-Wallis test and the Fisher's exact test. P < .05 denoted statistical significance.

Results

The accuracy of sonography and USgFNA was 64% and 68.8%, respectively. The sensitivity was 86.7% and 80%, respectively. Specificity was only 57.2% and 50%, respectively. The median ADC values for carcinoma and adenoma were 2.73 × 10⁻³ mm²/s and 1.93 × 10⁻³ mm²/s, respectively (P < .001). There was no significant difference between the median ADC value for Hashimoto thyroiditis (3.46 × 10⁻³ mm²/s) and carcinoma. An ADC value of 2.25 × 10⁻³ mm²/s or higher was proven to be the cut-off value for differentiating between benign and malignant cold thyroid nodules, with an accuracy of 88%, a sensitivity of 85%, and a specificity of 100%.

Conclusions

These results show that quantitative DWI is a more reliable diagnostic method for differentiation between benign and malignant thyroid lesions than sonography or USgFNA. However, further studies including a larger study population are necessary to confirm our study results.     

An abdominal and thyroid status with Acoustic Radiation Force Impulse Elastometry--a feasibility study: Acoustic Radiation Force Impulse Elastometry of human organs

Purpose

Acoustic Radiation Force Impulse (ARFI) is a new method for the quantification of tissue elasticity. To date, ARFI technology has not been applied systematically to establish an abdominal and thyroid status. The aim of this prospective feasibility study was to evaluate ARFI elastometry performed on various healthy abdominal organs and the thyroid gland.

Material and methods

94 patients (43 females, 51 males) with a mean age of 54 years and 20 healthy controls were enrolled in the study. A routine ultrasound examination of the abdomen was scheduled in 72, and of the thyroid in 25. ARFI elastometry was performed in liver, spleen, pancreas, prostate, kidneys and thyroid gland with the ultrasound system Acuson S2000. ARFI values are proportional to tissue elasticity. Patients with ultrasonic or anamnestic evidence of diseased organs were excluded from the analysis. ARFI measurements were compared with the aid of the t-test and correlated using Spearman's correlation coefficient.

Results

ARFI elastometry proved feasible and the measurements obtained in the various organs differed significantly. Among healthy organs the spleen showed the highest mean ARFI velocities, followed by the kidney, thyroid, pancreas and the prostate. The lowest ARFI values were regularly found in healthy liver. Measurements in the kidneys and the spleen showed high standard deviation.

Conclusions

ARFI elastometry may describe parenchymal stiffness of various abdominal organs and the thyroid gland. Further investigations are needed to compare these baseline findings in healthy organs with those of various tumours or diseases affecting the individual organs.     

Management of thyroid nodules: a clinicopathological,evidence-based approach

Management of thyroid nodules is one of the most controversial issues in thyroidology. Different approaches derive from geographical variation in presentation, inadequate or incomplete clinical diagnosis, lack of prospective controlled studies and, frequently, the different cultural backgrounds of physicians. This review aims to offer a practical approach to the management of nodular thyroid disorders, considering the way in which the pathophysiology of the disease provides clues to the correct clinical diagnosis and therapy.     

Interactive MR-guided biopsies of the thyroid gland: validation of a new method

The aim of this study was to demonstrate the clinical feasibility and utility of an interactive MR-guidance system to target and biopsy thyroid lesions, and to compare resolution between ultrasound and interventional MR imaging in the evaluation of thyroid lesions. Twenty thyroid lesions of 18 patients were interactively biopsied using a 0.5-T superconducting open magnet system. Stereotactic localization of the needle and imaging was accomplished using T1-weighted gradient-recalled-echo (GRE) images. Representative cytological material was retrieved in 16 of 20 lesions (benign cystic or colloid goiter: n = 14; one de Quervain's thyroiditis and one follicular neoplasia). Lesions smaller than 1.5 cm detected by ultrasound could not be visualized adequately on GRE images. Lesions smaller than 1.5 cm were successfully biopsied by ultrasound (three colloid and haemorrhagic goiters and one adenoma). Magnetic-resonance-guided interactive biopsies and positioning of non-ferromagnetic needles in the thyroid gland are technically feasible and safe. Compared with high-resolution ultrasound, lesions larger than 1.5 cm can be adequately visualized and biopsied. Magnetic-resonance-guided placement of non-ferromagnetic needles is no substitute for high-resolution ultrasound in clinical work-up of thyroid lesions. Received 1 December 1997; Revised 3 February 1998; Accepted 4 February 1998     

The value of acoustic radiation force impulse (ARFI) in the differential diagnosis of thyroid nodules

Objectives

The aim of this study was to investigate the value of shear wave velocity value (SWV) and shear wave velocity ratio (SWR) in differentiating between malignant and benign thyroid nodules using virtual touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) technology.

Methods

The SWV and SWR were analyzed in 155 thyroid nodules in 155 patients (93 benign and 62 malignant) and eighty normal thyroid glands. The diagnostic performance of SWV and SWR were compared.

Results

The mean value of SWV of malignant nodules differed significantly from those of the benign nodules (6.34 ± 2.58 m/s vs. 2.15 ± 0.59 m/s, P < 0.05) and the normal thyroid (1.96 ± 0.31 m/s, P < 0.05). There was no statistically significant difference between the mean value of SWV of benign nodules and normal thyroid (P > 0.05). The mean value of SWR of malignant nodules differed significantly from those of the benign nodules (2.99 ± 1.45 vs. 1.07 ± 0.34, P < 0.05). The sensitivity, specificity, positive predictive values, negative predictive values and accuracy of SWV in differentiating between malignant and benign nodules were 96.80%, 95.70%, 93.75%, 97.80% and 96.13% respectively based on the cutoff point as 2.84 m/s. Those of SWR were 91.90%, 81.70%, 77.03%, 93.83% and 85.83% based on the cutoff point as 1.32. The diagnostic accuracy rate of SWV was statistically higher than that of SWR (P < 0.05).

Conclusion

VTQ of ARFI technology provides the quantitative information of thyroid tissue elasticity and has high accuracy rate in differentiating between malignant and benign nodules. It is a useful complement for conventional ultrasonography.