Utility of Sonoelastography in Characterisation of Thyroid Nodules

Background: The majority of thyroid nodules that are inadvertently found are benign and asymptomatic. Though the malignant nodules make up 5% of thyroid nodules, they must be diagnosed accurately for clinical reasons. While conventional ultrasonography is a reliable method for identifying thyroid nodules, it is not possible to distinguish between benign and malignant nodules. The primary drawback of FNA cytology is that 10–15% of specimens are indeterminate and 10–15% are nondiagnostic. FNA cytology is invasive and vulnerable to errors in sampling and analysis. Thus, there is a need to enhance and perfect non-invasive techniques to diagnose malignant lesions. Palpable thyroid nodule stiffness is a subjective measure that cannot reliably predict cancer. It has been demonstrated that sonoelastography is helpful in differentiating between benign and malignant tumours. In contrast to the surrounding normal tissues, the majority of benign tumours are softer, whereas the majority of malignant tumours are stiff and hard. Thus, the purpose of this study was to illustrate the diagnostic precision and usefulness of sonoelastography in identifying thyroid nodules that are benign or malignant. Methods: This cross-sectional study, which involved 41 patients with thyroid nodules was carried out in the radiology department of a tertiary care hospital between September 2017 and October 2018. Strain sonoelastography was carried out during the conventional ultrasound examination of the thyroid gland. The ‘Rago’ criteria-based sonoelastography colour scoring system was applied. The trial participants subsequently had a ultrasound-guided FNA cytology of the lesions. SPSS 22 version software was used for data analysis after the data was entered into a Microsoft Excel data sheet. Frequencies and proportions were used to depict categorical data. For qualitative data, the chi-square test or Fischer's exact test was employed as the significance test. The mean and standard deviation were used to depict continuous data. Data visualisation was done using Microsoft Word and Excel to create a variety of graphs, including pie charts and bar charts. Results: The majority of these individuals (41.5%) were in the age range of 31 to 40. 90.2% of the patients were female. In the B-mode, there were 5.1% malignant lesions, 23.7% indeterminate lesions, and 71.2% benign lesions. 13.6% of elastography scores were 1, 66.1% were 2, 10.2% were 3, 8.5% were 4, and 1.7% were 5. 10.2% of the lesions were determined to be malignant and 89.8% to be benign based on the elastography scores. In reference to sonoelastography, only 66.7% of the malignant lesions and 33.3% benign lesions were found to be picked up in B-mode sonography; similarly, among those indeterminate lesions of B-mode sonography, 14.3% were found to be malignant and 85.7% to be benign on sonoelastography; and among those benign lesions of Bmode sonography, 4.8% were found to be malignant and 95.2% were benign by sonoelastography. Among the thyroid nodules, 88.1% of lesions were found to be benign based on FNAC/HPE, whereas 11.9% were found to be malignant. Colloid goitre (22%), papillary carcinoma (10.2%), and follicular carcinoma (1.7%) made up the majority of the study findings, with hyperplastic nodules accounting for 66.1%. All the malignant lesions identified by B-mode sonography were found to be concordant in HPE (100%); 14.3% of those with B-mode indeterminate lesions were found to be malignant by FNA cytology/ HPE and 85.7% to be benign; 2 benign lesions of B-mode (4.88%) were found to be malignant. Thus, the B - mode sonography had a sensitivity of 42.86%, specificity of 100%, PPV of 100%, NPV of 95.24% with diagnostic accuracy of 95.56% in diagnosis of malignant lesions in comparison with HPE. Sonoelastography showed a sensitivity of 85.71%, specificity of 100%, PPV of 100%, NPV of 98.1% with diagnostic accuracy of 98.3% in the diagnosis of malignant lesions in comparison with HPE. Combined sonoelastography and B Mode sonography showed a 100% sensitivity, specificity and NPV of 100% with diagnostic accuracy of 100% in diagnosis of malignant lesions in comparison with HPE. Conclusion: An imaging method that shows promise for characterising thyroid nodules is sonoelastography. When B-mode and sonoelastography are used together, the outcomes are superior to when they are used separately.