الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 113 |  |  |
| | | from | 113 | | |
Abstract
This study was conducted on fifty four patients with thyroid nodules detected by palpation or incidentally noted during neck imaging for other reasons. There were 12 males (22.2%) and 42 females (77.8%). Their ages ranged form 19 to 76 years with a mean of 45.15 years and a median of 44 years.
The aim of this work was to study the role of ultrasound and Doppler in selection of patients with thyroid nodules candidate for FNA.
All patients were subjected to full history taking, thorough clinical examination and laboratory investigations. Gray scale Ultrasound and Doppler examination were done to all patients. Sixteen patients were further evaluated by Elastography. All patients underwent FNA, of which, forty nine had thyroidectomy ± neck dissection.
The risk factors of thyroid malignancies include age younger than 20 or older than 60 years, male sex and family history of thyroid malignancy.
The most common type of thyroid malignancies was papillary carcinoma found in ten patients.
Gray scale Ultrasound is very useful to demonstrate the characteristics of thyroid nodules including their number, size, shape, composition, texture, echogenicity, margins, halo, calcifications and the presence of suspicious-appearing lymph nodes. We found a sensitivity of 16% and specificity of 100% for marked hypoechogenicity, a sensitivity of 44% and specificity of 98.15% for microcalcifications, a sensitivity of 40% and specificity of 98.15% for irregular margin, a sensitivity of 20% and specificity of 98.15% for lobulated margin and a sensitivity of 60% and specificity of 68.63% for hypoechogenicity. The presence of more than one of the above features, however, increases the probability that a thyroid nodule represents a malignancy. The presence of suspicious cervical lymph nodes also had a high specificity of 100% and a sensitivity of 52.17%. On the other hand, there was no statistical significance between the size, echotexture, coarse calcification and the number of nodules and the presence of malignancy in the current study.
Color Doppler ultrasound has become an established imaging technique for assessing the thyroid gland. from the analysis of our results, it can be seen that the malignant nodules predominantly had central vascularization (type IV), whereas the benign nodules predominantly had peripheral vascularization (type II and III). These associations had positive statistical significance and agree with most other studies that we have reviewed. However, Doppler characteristics could not be used to rule out malignancy because 28% of the malignant nodules had predominantly peripheral flow. The sensitivity and specificity of type IV vascularity in detection of malignant thyroid nodule were 52% and 94.4% respectively.
Using spectral wave analysis, we found that the resistive index (RI) was useful in differentiating benign and malignant nodules. For predicting malignancy, the higher the RI value, the higher the accuracy, specificity, and positive predictive value and the lower the sensitivity and negative predictive value. An RI cutoff of 0.7 had accuracy, sensitivity, specificity, and negative and positive predictive values of 82.25%, 55%, 100%, 82%, and 100%, respectively.