The use of sonoelastographic elasticity index to differentiate benign and malignant thyroid nodules

• Published in: Japanese journal of radiology Vol. 31; no. 11; pp. 750 - 754
• Main Authors: Boyaci, Nurefsan, Karakas, Ekrem, Sen Dokumaci, Dilek, Kocarslan, Sezen, Yildiz, Sema, Cece, Hasan, Eren, Mehmet Ali
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01-11-2013; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Biopsy, Fine-Needle; Carcinoma, Papillary - diagnosis; Carcinoma, Papillary - surgery; Diagnosis, Differential; Elasticity; Elasticity Imaging Techniques - methods; Female; Humans; Imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Nuclear Medicine; Original Article; Predictive Value of Tests; Prospective Studies; Radiology; Radiotherapy; Sensitivity and Specificity; Thyroid Neoplasms - diagnosis; Thyroid Neoplasms - surgery; Thyroid Nodule - diagnosis; Thyroidectomy; Treatment Outcome; Sonoelastography; Thyroid papillary carcinoma; Fine needle aspiration biopsy
• ISSN: 1867-1071; 1867-108X
• DOI: 10.1007/s11604-013-0248-y

Purpose
The aim of this study is to evaluate the elasticity index of thyroid nodules by sonoelastographic imaging, and to determine the cut-off value to distinguish malignant nodules from benign nodules with optimum sensitivity and specificity.
Materials and methods
Fine needle aspiration biopsy (FNAB) of 84 cases were evaluated with B-mode US and Sonoelastography (USE) preoperatively. The elasticity score (ELX 2/1) index of the nodules were calculated. Seventy-three patients with diagnostic biopsy results were included in this study.
Results
According to the FNAB results, 9 (12 %) nodules were malignant, 64 (88 %) nodules were benign. All malignant nodules were papillary carcinoma, and their diagnosis was confirmed with thyroidectomy. The ELX 2/1 index of all malignant nodules was higher than 1.65. The ELX 2/1 index of 45 (70.3 %) benign nodules was lower than 1.65 whereas the ELX 2/1 index of 19 (29.7 %) benign nodules was higher than 1.65. Using an ELX 2/1 index cut-off value of 1.65 led to a sensitivity of 100 % and a specificity of 71 % in detecting papillary thyroid carcinomas.
Conclusions
Assessing the ELX 2/1 index as a screening test and deciding on FNAB accordingly, in addition to gray-scale ultrasound findings of the nodules, will be beneficial in order to prevent unnecessary biopsies.