الفهرس 
Anatomy of the Thyroid GlandOnly 14 pages are availabe for public view
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Abstract
Thyroid nodules are common in general population. The incidence of these nodules is being dramatically increased in iodine-deficient areas. Most of these nodules are benign with less than 5% of them are malignant.
Fine needle aspiration (FNA) cytology is a standard method in differentiation between benign and malignant thyroid nodules due to its high sensitivity and specificity. But it has some limitations as some of specimens are indeterminate and not diagnostic so, many of its results become not conclusive.
B-Mode US is a widely used technique in thyroid patients due to its ability to detect non-palpable nodules, estimate nodule size-shape and also its ability in differentiation between solid and cystic lesions.
In our study, the most sonographic characters that suggest malignancy are: irregular margin, marked hypo echogenicity, nodular shape that was taller than wide and absence of halo sign.
Ultrasound elastography is a newly developed technique that has been used in evaluation of thyroid nodules. It can measure the degree of tissue stiffness as pathological tissues are usually harder than normal tissues. The US elastogram was displayed over the B- mode image which can be represented as a colored map ranging between red and blue depending on tissue elasticity.
Our study includes 100 patients with 146 indeterminate thyroid nodules and all of them are subjected to complete U/S, color Doppler examination, and US elastography, the results were compared to U/S guided FNAC.
The results using ultrasound elastography to distinguish benign from malignant thyroid nodules are overall encouraging, offering non-invasive complementary information to B- mode US. Heterogeneous results of available studies are at least in part due to selection bias (varying percentages of malignant nodules) and use of non-uniform scoring systems (e.g. 4 point or 5-point elasticity score, stiffness index). In order for these promising preliminary results to gain widespread clinical application, further validation with large cohort prospective studies and standardization of techniques are necessary.
Finally, we concluded that US-elastography is a promising technique that, combined with other US modalities, is easy and rapid to perform and could be used in clinical diagnosis as a noninvasive diagnostic approach, which may lead to a great improvement in accurate diagnosis, and for benign thyroid nodules, the number of unnecessary surgical procedures could be reduced.
In our opinion, further studies are necessary before being able to conclude about the place of elastography in thyroid nodules evaluation, versus fine-needle aspiration cytology (FNAC), the gold standard. Indeed, elastography could reduce FNAC or at least allow to select nodule’s (or nodular zone’s) for aspirations.