Quantitative evaluation of contrast-enhanced ultrasound after intravenous administration of a microbubble contrast agent for differentiation of benign and malignant thyroid nodules: assessment of diagnostic accuracy

Correlation between maximum intensity and microvessel density for differentiation of malignant from benign thyroid nodules on contrast-enhanced sonography

OBJECTIVES

The purpose of this study was to retrospectively evaluate contrast-enhanced sonography for differentiation of benign and malignant thyroid nodules by analyzing the correlation between maximum intensity and microvessel density.

METHODS

From February 2010 to May 2012, 122 patients (85 female and 37 male; mean age ± SD, 45 ± 9.1 years) with thyroid nodules (62 papillary thyroid carcinomas, 30 nodular goiters, and 30 adenomas) that underwent routine thyroid sonography and were diagnosed by surgery were included in this study. Contrast-enhanced sonography was performed, and enhancement patterns were classified into 3 groups: high, equal, and low enhancement. As a time-intensity curve parameter, the correlation of maximum intensity with CD31 and CD34 microvessel density counts was analyzed.

RESULTS

On contrast-enhanced sonography, most patients with papillary thyroid carcinomas showed a heterogeneous low enhancement pattern, whereas most patients with nodular goiters showed an equal enhancement pattern, and patients with adenomas showed a high enhancement pattern. The detection of papillary thyroid carcinomas with low enhancement had sensitivity of 96.8%, specificity of 95.0%, and accuracy of 95.9%. Compared with the papillary thyroid group, the mean microvessel density counts were significantly higher in the nodular goiter and adenoma groups (P< .05). We also found that the maximum intensity was significantly associated with CD31 and CD34 counts (CD31, r = 0.963; P < .01; CD34, r = 0.968; P < .01).

CONCLUSIONS

Maximum intensity has a significant relationship with microvessel density. Contrast-enhanced sonography is a practical and convenient means for differentiating benign from malignant thyroid nodules.

Comparison of diagnostic efficacy of contrast-enhanced ultrasound, acoustic radiation force impulse imaging, and their combined use in differentiating focal solid thyroid nodules

BACKGROUND

A key limitation of conventional ultrasound (US) includes poor differentiation of benign from malignant thyroid nodules. Contrast-enhanced US (CEUS) and acoustic radiation force impulse (ARFI) could provide better characterization of focal thyroid nodules; however, no studies have compared their efficacies.

OBJECTIVE

To evaluate the diagnostic efficacy of conventional US,CEUS, ARFI, and their combined use in differentiating focal solid thyroid nodules.

METHODS

One-hundred-forty-six Chinese patients with 175 thyroid nodules (119 benign and 56 malignant) were prospectively enrolled. Each patients underwent conventional US, CEUS and ARFI, respectively. The diagnostic performance of the conventional US, CEUS, ARFI, combined use of either CEUS or ARFI and combined use of the three modalities were assessed and compared using Pathological diagnosis (histological/cytological) as the reference method.

RESULTS

There were no significant differences between individual groups (CEUS vs US, P = 0.279, ARFI vs US, P = 0.372, CEUS vs ARFI, P = 0.849), combined use of US and CEUS or combined use of US and ARFI yielded significant difference compared to US. (combination of US & CEUS vs US, P = 0.021; combination of US & ARFI vs US, P = 0.036). The combination of three modalities significantly improved the diagnostic accuracy compared with either combination of conventional US and CEUS or combination of conventional US and ARFI (P = 0.045 and P  = 0.027, respectively).

CONCLUSIONS

CEUS and ARFI can be used as an additional tool in the diagnostic work up of thyroid nodules. The combination of CEUS with ARFI can significantly improve the diagnostic accuracy.

Diagnostic performances of various gray-scale, color Doppler, and contrast-enhanced ultrasonography findings in predicting malignant thyroid nodules

BACKGROUND

Ultrasonography is the most frequently used clinical tool for the identification, assessment, and follow-up of thyroid nodules. The purpose of this research was to evaluate the value of diagnostic ultrasonography indicators, to obtain rankings of the most valuable indicators in the differential diagnosis of thyroid nodules, and to analyze the optimal diagnostic points and clinical values.

METHODS

One hundred forty-four patients with 172 thyroid nodules underwent preoperative ultrasonography examinations, including gray-scale ultrasonography (GSUS), color Doppler ultrasonography (CDUS), and contrast-enhanced ultrasonography (CEUS). Fourteen indicators of thyroid nodules on GSUS, CDUS, and CEUS were selected to evaluate all thyroid nodules. The differences between the benign and malignant thyroid nodules in all indicators were analyzed by the chi-squared test; the diagnostic ultrasonography values were obtained by logistic regression; and the optimal diagnostic points were explored by receiver operating characteristic curve analysis.

RESULTS

Of the 172 thyroid nodules that were surgically removed, 78 were benign and 94 were malignant. Ten indicators of GSUS and CEUS showed significant differences between the benign and malignant nodules (p<0.05), whereas four CDUS indicators had no value. The rankings of the valuable indicators were obtained according to their odds ratios (ORs). The top four indicators were ring enhancement and homogeneity of enhancement on CEUS, and microcalcification and halo on GSUS. These indicators were the most valuable, with ORs of greater than 20 in the differential diagnosis of benign and malignant thyroid nodules. The other six indicators-the relative arrival time of the nodule on CEUS, interior echogenicity on GSUS, peak interior echogenicity on CEUS, shape on GSUS, peak peripheral echogenicity on CEUS, and orientation on GSUS-were also valuable, with ORs less than 20. The areas under the receiver operating characteristic curves for GSUS, CEUS, and the combination of GSUS and CEUS in the diagnosis of thyroid nodules were 0.936, 0.910, and 0.966, respectively. Five positive features of the 10 valuable indicators on GSUS and CEUS defined the cut-off for the diagnosis of malignant thyroid nodules, with a sensitivity of 89.4% (84/94), specificity of 93.6% (73/78), and accuracy of 91.3% (157/172).

CONCLUSIONS

The ring enhancement and homogeneity of enhancement of thyroid nodules on CEUS and the microcalcification and halo on GSUS were the four most valuable indicators in the differential diagnosis of thyroid nodules. Conjoint analysis of specific features of thyroid nodules on GSUS and CEUS could enhance the diagnostic value of thyroid nodules.