Clinical Evaluation of Color Doppler Imaging for the Differential Diagnosis of Thyroid Follicular Lesions

Abstract

Ultrasonography (US) of the thyroid gland has recently proved to be a useful clinical diagnostic method, and the newly developed high-resolution US with a color Doppler flow mapping function can reveal fine details of the thyroid gland and the hemodynamic features of a thyroid neoplasm. US can yield a diagnostic accuracy of more than 90% for thyroid carcinoma, especially papillary carcinoma. However, neither conventional B-mode US imaging nor aspiration biopsy cytology has delivered satisfactory results for follicular carcinoma. The aim of this study was to evaluate the clinical usefulness of color Doppler imaging for the differential diagnosis of thyroid follicular lesions. A color Doppler scan was performed in 310 patients with a solitary cold nodule, and a combination of B-mode US and color Doppler findings, including tumor vascularity and results of a fast Fourier transform (FFT) analysis were used to create the following diagnostic grading system for differential diagnosis of follicular lesions: grade 1, benign follicular lesion [no color flow mapping (CFM) inside the nodule]; grade 2, benign peripheral type [CFM only in peripheral area, pulsatility index (PI) < 1.0]; grade 3, suspected follicular carcinoma (penetrating CFM, vascularity moderate); grade 4, follicular carcinoma (high-velocity penetrating CFM, PI = 1.0). All patients were subjected to surgical resection, and histologic examination was used to confirm the diagnosis. The grades of the 177 adenomatous nodules were as follows: grade 1, 46.9%; grade 2, 48.0%; grade 3, 5.1%; grade 4, 0%. The corresponding percentages for the 89 follicular adenomas were 16.9%, 49.4%, 30.3%, and 3.4%; and for the 44 follicular carcinomas they were 0%, 13.6%, 45.5%, and 40.9%. On the assumption that grade 1 and 2 lesions are benign and grade 3 and 4 lesions are malignant, 38 of the 44 follicular carcinomas and 227 of the 266 benign tumors had been accurately diagnosed, yielding a sensitivity of 88.9%, a specificity of 74.2%, and an accuracy of 81.0% for the grading system. Color Doppler imaging of 310 follicular tumors has revealed that high-velocity pulsatile blood flow penetrating the tumor is a characteristic finding of follicular carcinoma and is a new diagnostic criterion for performing color Doppler imaging. The differential diagnostic grading scores for color Doppler examinations and the results of FFT analysis demonstrate that US with the color Doppler function can play an important role in the differential diagnosis of thyroid tumors.

Ultrasound-Based Diagnostic Classification for Solid and Partially Cystic Thyroid Nodules

“…Furthermore, there was a high incidence of papillary thyroid carcinoma (95.2%, 299/314), which may introduce a bias because generally accepted malignant US features are not helpful for diagnosing follicular carcinoma. 26,27 Finally, all US evaluations were performed by a single radiologist. Therefore, large-scale multicenter studies are recommended to ensure reproducibility.…”

Thyroid Cancers: Considerations, Classifications, and Managements

“…A larger size and increased intranodular vascularity on color or power Doppler imaging are also predictive of malignancy [109][110][111][112].…”

Metástases Cutâneas de Carcinoma de Células de Hürthle da Tiróide

“…19 A vascular appearance has indeed been identified in these lesions, to the point of even showing a pulsatile character upon Doppler echography. 20 In the differential diagnosis, several benign and malignant lesions should be evoked, including angioma, pyogenic granuloma, Kaposi's sarcoma, angiosarcoma, renal cell and hepatocarcinoma scalp metastases. 21 Final diagnosis is however established by histological examination of a tissue specimen with additional immunohistochemical and/or EM approaches, in order to clearly ascertain the nature and origin of the primary malignancy.…”