The Clinical Significance of Ultrasonography and Computed Tomography in Diagnosis of Thyroid Nodule

Tae, Kyung; Lee, Hyung Seok; Choi, Suk Joo; Park, Joon Soo; Ahn, Kyung Sung; Park, Dong Woo

Abstract

BACKGROUND: The workup of thyroid nodule is complex, and there are many and varied indications for thyroid imaging. Ultrasonography is first-line structural investigative modality in thyroid nodular disease. It can effectively differentiate a solid from a cystic lesion. Ultrasonography is also the best study available to measure nodule size. Computed tomography provides useful information about the extension of thyroid nodules and regional lymph node involvement or local recurrence.
OBJECTIVES
We analysed Ultrasonographic(US) and Computed Tomographic(CT) findings of thyroid nodule to determine the difference between a benign and a malignant mass and to evaluate the differential findings, if any.
MATERIALS AND METHODS
The subjects were 80 cases with a pathologically proven thyroid nodule(US in 47 cases, CT in 33 cases) at the Hanyang University Medical Center, from July 1995 to July 1996. US and CT findings were retrospectively analysed about size, multiplicity, solid and cystic change, margin, calcification, and invasion of adjacent structures. Statistical analysis was performed using the chi-square and Fisher's exact test.
RESULTS
1) Invasion of adjacent structures was observed in 4 cases(25%) in CT, and it was proved statistically significant finding of malignacy. 2) Thyroid nodule with cervical lymphadenopathy was observed in 4 cases(25%) in CT, and it was proved as significant finding of malignancy. 3) The solid pattern of thyroid nodules was observed in 13 cases(81.3%) in CT, and it was proven statistically significant finding of malignancy. 4) The other findings of CT and US which were examined, showed no statistically significant correlation between benignancy and malignancy.
CONCLUSION
CT has a significant role of differentiation between benign and malignant tumor of thyroid gland by detection of invasion of adjacent structures, solid pattern, and cervical lymphadenopathy.