Ultrasound Thyroid Elastography Using Carotid Artery Pulsation

Abstract

Objective. The purpose of this study was to evaluate the feasibility of ultrasound thyroid elastography using carotid artery pulsation as the compression source and its potential for differential diagnosis of thyroid nodules. Methods. Baseband sonographic data were acquired for 16 thyroid nodules from 12 patients. The natural pulsation of the carotid artery was used as the compression source, and thyroid strain was estimated offline. For quantitative assessment of thyroid tissue stiffness, a new metric called the thyroid stiffness index (TSI) was computed as the ratio of strain near the carotid artery (high-strain region) to that of a stiff region (low-strain region) inside a thyroid nodule. The stiffness information from elastography was correlated with histopathologic findings. Results. The TSI for papillary carcinoma (n = 9) was higher than the TSI for a benign nodular goiter (n = 6), indicating that papillary carcinoma is stiffer than a benign nodular goiter (P < .05). In 1 patient, we were able to distinguish a papillary carcinoma nodule and a benign nodular goiter located in the same thyroid lobe based on the stiffness information obtained from elastography. This suggests that elastography could be used for guiding fine-needle aspiration biopsy to a thyroid nodule with a high probability of cancer. Conclusions.The results from this preliminary study indicate the feasibility of the pulsation-induced thyroid elastography. Ultrasound thyroid elastography using carotid artery pulsation appears to have the potential for noninvasively differentiating papillary carcinoma from benign nodular goiter. Future studies are needed to evaluate the efficacy of elastography in detecting thyroid cancer and guiding thyroid biopsies. Key words: carotid artery pulsation; elastography; thyroid; thyroid stiffness index; ultrasound.Received February 5, 2007,

The role of sonoelastography in the differential diagnosis of neck nodules

“…Numerous studies are being conducted on the use of this method for the assessment of other organs, superficial and deep [11e17]. Elastographic characterization of thyroid nodules seems to be particularly useful in clinical practice, since conventional sonography provides very little information on the benign or malignant nature of these lesions [5,11,13]. Use of this technique for studying other structures in the neck (lymph nodes, salivary glands) has not been extensively studies, and additional data based on the analysis of larger series are needed.…”

“…Lyshchik et al [1] obtained promising results with an experimental technique and equipment, which were highly interesting within a research context, but the approach they used is too complex and time-consuming for routine use in clinical practice. In contrast, Bae et al [11] have proposed an alternative to the widely used approach that involves manual compression. They showed that carotid artery pulsation can be exploited as a source of compressive stress on thyroid tissues.…”

Thyroid Ultrasound: State of the Art. Part 2 – Focal Thyroid Lesions

“…The TSI or papillary carcinoma was higher comparing with benign nodular goiter, indicating that papillary carcinoma is stiffer than a benign nodular goiter [48].…”

“…Elastography could guide the thyroid FNA biopsy to improve the sensitivity and specificity of the FNA in thyroid cancer detection and reduce the number of cases having an insufficient number of tissue samples for diagnosis [48]. …”

Clinical Importance of Diastolic Sonoelastographic Scoring in the Management of Thyroid Nodules

“…2,3 Several research groups used the natural vascular pulsation of the carotid artery as the internal compression source and determined a nodule strain index. 4,5 Nevertheless, evaluation of nodules with this method is a laborious and time-consuming procedure not performed in real-time. Other researchers used the manual external compression method with a random phase approach on the thyroid region and scored the nodules.…”