Clinical Value Of Real Time Contrast-enhanced Ultrasound In The Diagnosis Of Thyroid Solid Nodules

Clinical value of real time contrast-enhanced ultrasound in the diagnosis of thyroid solid nodulesObjectives1. To observe and summarize the enhancement patterns and perfusion characteristics of thyroid solid nodules with real time contrast-enhanced ultrasound (CEUS).2. To investigate the clinical value of CEUS in the diagnosis of thyroid nodules.3. To compare the diagnostic role of real time CEUS and conventional ultrasound in the differentiation of benign and malignant thyroid nodules.MethodsReal time CEUS and conventional ultrasound were used to examine 146 thyroid nodules (including 85 malignant and 61 benign nodules) in 128 patients, all of which were confirmed by operation and pathology. The CEUS examination was performed with PHILIPS iU22 ultrasound system with a 3-9MHz wideband transducer. CEUS presets were adjusted as follows:mechanical index (MI) 0.08-0.10, total gain 88%-90%, depth 3.5 cm, and the focus distal to the lesion with Xres and SonoCT enabled. After a bolus administration of 1.5 mL SonoVue through the antecubital vein, the CEUS examination was recorded digitally.After reviewing dynamic images of CEUS, enhancement time, enhancement degree, intranodular and peripheral enhancement patterns of thyroid nodules were recorded. The enhancement findings of thyroid nodules on CEUS were analyzed and compared with the histological results. In addition, the sensitivity, specificity, positive predictive value, and negative predictive value of CEUS in the diagnosis of benign and malignant thyroid solid nodules were calculated and compared with those of conventional ultrasound.Results1. The enhancement patterns and perfusion characteristics of thyroid solid nodules on CEUSThe enhancement was identified in 145 of 146 thyroid nodules after SonoVue administration. Totally,73.7% (45/61) benign nodules enhanced earlier than or were synchronized with the surrounding thyroid tissue, and 56.4% (48/85) malignancy enhanced later than thyroid tissue. The holistic homogeneous enhancement presented in 59.0% (36/61) benign lesions and regional enhancement in 74.1% (63/85) malignancy nodules. There were 68.9%(42/61) benign nodules showing higher or similar enhancement compared to thyroid tissue and 72.9% (62/85) malignancies showing lower enhancement. And 54.1% (33/61) benign nodules showed rim-like enhancement and 98.8%% (84/85) malignancies were lack of rim-like enhancement.2. The diagnostic value of CEUS in the thyroid nodulesIf intranodular enhancement later than that in the surrounding thyroid tissue was a criteria for malignancy, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CEUS were 56.4%,73.8%,76.2% and 54.9%, respectively. If intranodular lower enhancement compared to the thyroid tissue was suggestive of malignancy, the sensitivity, specificity, PPV and NPV of CEUS were 72.9%, 68.9%,76.5% and 64.6%, respectively. If intranodular heterogeneous enhancement was suggestive of malignancy, the sensitivity, specificity, PPV and NPV of CEUS were 91.8%, 59.0%,75.7% and 83.7%, respectively. If rim-like enhancement was suggestive of benign lesion, the sensitivity, specificity, PPV and NPV of CEUS were 54.1%,98.8%,97.0% and 75.6%, respectively.3. Comparison of real time CEUS and conventional ultrasound in the diagnosis of thyroid solid nodulesIf conventional ultrasound was used only in diagnosing thyroid nodules, the sensitivity, specificity, PPV and NPV were 88.2%,88.5%,91.5% and 84.4%, respectively. If color Doppler ultrasound was used only in diagnosing thyroid nodules, the sensitivity, specificity, PPV and NPV were 84.7%,85.2%,88.9% and 80.0%, respectively. If CEUS was used only in diagnosing thyroid nodules, the sensitivity, specificity, PPV and NPV were 85.9%,85.2%, 89.0% and 81.3%, respectively. If conventional ultrasound and color Doppler ultrasound were combined in diagnosing thyroid nodules, the sensitivity, specificity, PPV and NPV were 91.7%,91.8%,93.9% and 88.9%, respectively. If the combination of CEUS, conventional ultrasound and color Doppler ultrasound was used in diagnosing thyroid nodules, the sensitivity, specificity, PPV and NPV were 94.1%,93.4%,95.2% and 91.2%, respectively.Conclusions1. The enhancement characteristics of thyroid malignant and benign nodules are different on CEUS.2. CEUS is valuable in differentiating benign and malignant thyroid nodules clinically.3. The sensitivity and specificity of combination of CEUS, conventional ultrasound and color Doppler ultrasound are superior to conventional ultrasound, color Doppler ultrasound or CEUS. CEUS provides more information for clinical diagnosis and management of thyroid nodules. It is a necessary complement and development for conventional ultrasound.