Incidental Detection of Thyroid Nodules at Magnetic Resonance Imaging of the Cervical Spine

Abstract

The incidental detection of thyroid lesions in patients undergoing magnetic resonance (MR) imaging of the cervical spine was prospectively evaluated on 389 MR images. Sagittal images extended from the cranio-cervical junction to the upper thoracic level, and axial images from C3-4 to C7-T1 intervertebral levels. Twenty patients (5.1%) had a total of 26 thyroid nodules. Eighteen patients presented with a single dominant nodule, of whom 2 had a multinodular gland with a single dominant nodule (one had 3 and the other had 5 nodules). Two patients had diffusely enlarged gland without a dominant nodule. The mean size of the nodules was 11.6 mm. One thyroid nodule was detected at the C5-6 intervertebral level, 14 at the C6-7, and 11 at the C7-T1. T 2 -weighted imaging was more useful than T 1 -weighted imaging for the detection of thyroid nodules because of the hyperintense versus isointense appearance of the lesions. Thyroid carcinoma was identified at surgery in one patient. The detection rate was low compared with computed tomography with contrast medium and ultrasonography. Our results suggest that MR imaging has limited value for the detection of thyroid lesions and that the presence of such lesions cannot be denied based only on MR imaging of the cervical spine. However, asymptomatic thyroid lesions, including thyroid cancer, can be identified on MR images of the cervical spine, so we recommend that evaluation of these images should consider such lesions.

Characteristics of Incidentally Discovered Thyroid Cancer

“…8,11 For incidental thyroid nodules found by CT and MRI, reported malignant carcinoma rates range from 3.9% to 11.3%. 7,[12][13][14] Thyroid incidentalomas on PET imaging have reported malignant carcinoma rates ranging from 13.6% to 62.5%. 9,12,15,16 Some studies have looked at thyroid incidentalomas as diagnostic dilemmas, discussing approaches for patients with an incidental thyroid lesion.…”

Incidental Thyroid Nodules: Incidence, Evaluation, and Outcome

“…4-6 Specifically, incidentally discovered thyroid nodules (IDTNs), defined as asymptomatic nonpalpable thyroid lesions that are discovered on an imaging study unrelated to the thyroid gland, have become more prevalent. 7,8 IDTNs are reported to be present on 16% of computed tomography (CT) and magnetic resonance (MR) scans, 9,10 9% of carotid ultrasound (US), 11 and 3% of positron emission tomography (PET) scans. 12 The clinical and oncologic significance of these nodules, however, remains unclear.…”

Prevalence of incidental thyroid abnormalities in patients with degenerative cervical spondylosis: a retrospective cross-sectional magnetic resonance imaging study

“…In a survey of 30 provinces and regions in China, the prevalence of thyroid nodules was reported to be as high as 36.9% in the normal population who underwent US ( 11 ). Kim et al ( 8 ) reported that the prevalence of incidental thyroid abnormalities on cervical spine MRI scans was 5.1% in their 389 participants. However, the population in their study included patients who underwent cervical spine MRI for any reason.…”

“…If the patient is aged ≥35 years, the size for further evaluation is raised to 1.5 cm, and all enlarged thyroid glands should undergo further workup with dedicated US ( 3 ). However, to date, few studies have reported the prevalence of incidental thyroid abnormalities focused on MRI, and the prevalence in cervical spine MRI in the literature ranges widely, from 5.1% to 49.6% ( 7 , 8 ). In anterior cervical surgery, vigorous mobilization of the thyroid gland, especially the development of a goiter, may damage the recurrent laryngeal nerve ( 9 ).…”