Sonographic Assessment of the Extent of Extrathyroidal Extension in Thyroid Cancer.

OBJECTIVE: This study aimed to determine the sonographic features suggestive of extrathyroidal extension (ETE) of thyroid cancers. MATERIALS AND METHODS: We retrospectively reviewed the sonographic images of 1656 consecutive patients who had undergone thyroidectomy in 2017. The diagnostic performance of sonographic features suggestive of ETE was evaluated using operation and histopathologic reports. Sonographic features for gross ETE to the strap muscle and minor ETE were assessed for thyroid cancer abutting the anterolateral thyroid capsule. Sonographic features for tracheal invasion were assessed according to whether the angle between the tumor and the trachea was an acute, right, or obtuse angle. Sonographic features for recurrent laryngeal nerve (RLN) invasion were assessed based on the association between the tumor and tracheoesophageal groove (TEG) as preserved normal tissue, abutting or protruding into the TEG. RESULTS: ETE was observed in 783 patients (47.3%), including 123 patients with gross ETE (7.4% [strap muscle, n = 97; RLN, n = 24; and trachea, n = 14]) and 660 patients with minor ETE (39.9%). Regarding the diagnosis of gross and minor ETE to the strap muscle, sonographic features of replacement of the strap muscle and capsular disruption showed the highest positive predictive value (75.9% and 58.5%, respectively). Thyroid cancer forming an obtuse angle with the trachea had the highest sensitivity for the diagnosis of tracheal invasion (85.7%), and thyroid cancer protrusion into the TEG showed the highest sensitivity for the diagnosis of RLN (83.3%). CONCLUSION: Sonography is considered beneficial in the diagnosis of ETE to the strap muscle, trachea, and RLN. Assessment of ETE is important for the accurate staging of thyroid cancer, which in turn determines the extent of surgery or whether active surveillance is appropriate or not.

MR assessment of oral cavity carcinomas.

Approximately half of head and neck carcinomas arise from the oral cavity. Imaging plays an essential role in the preoperative evaluation of oral cavity carcinomas. MR imaging is particularly advantageous in the evaluation of the oral cavity, with better depiction of the anatomy in this region and reduction of dental artifacts compared with CT. MR is also the preferred imaging modality for the evaluation of bone marrow invasion and perineural tumor spread, which are findings critical for treatment planning. Advanced MR imaging techniques may potentially better delineate true tumor extent, determine lymph node metastases, and predict treatment response.

Electrophysiological assessment of compressive lesions of anterior visual pathways.

The findings in the pattern reversal V.E.C.P.'s have been examined in thirteen (13) patients, with proven or suspected pituitary tumours. Three (3) of these cases have been examined in detail, to highlight the unique capabilities of the pattern reversal V.E.C.P. in the assessment of conduction abnormalities of optic nerve and chiasma, due to compression by pituitary tumours. The V.E.C.P. is shown to be a uniquely sensitive procedure, which yields objective and quantitative data about the functional status of the anterior visual pathways, in cases of suspected compression by pituitary tumours. It is suggested that subclinical optic nerve compression is best detected by serially monitoring optic nerve conduction with the pattern reversal V.E.C.P.