Three-dimensional sonography in the evaluation of primary hyperparathyroidism

Virtual evaluation of selected cervical lymph nodes with three-dimensional ultrasound in thyroid cancer patients after thyroidectomy

BACKGROUND

We evaluated the usefulness of three-dimensional (3D) ultrasound of cervical lymph nodes (LN), when two-dimensional (2D) ultrasound evaluation is not sufficient to clearly evaluate lymph node characteristics, in thyroid cancer patients being followed after thyroidectomy.

METHODS

Two readers retrospectively analyzed 2D and 3D images of 147 LNs; LNs were categorized as normal, reactive, suspicious, or indeterminate, and confidence level was rated. Results were compared to cytological/clinical data. Inter-reader agreement was calculated.

RESULTS

Addition of 3D ultrasound significantly increased specificity (0.787 with 2D ultrasound vs 0.905 with 2D + 3D ultrasound for reader 1, P = .009; 0.701 with 2D ultrasound vs 0.898 with 2D + 3D ultrasound for reader 2, P = .01). Addition of 3D ultrasound significantly increased confidence level of readers (P < .001). Inter-reader agreement in LN categorization was almost perfect with 2D + 3D ultrasound.

CONCLUSION

3D ultrasound of cervical LNs enables better demonstration of imaging features that are important in differentiating benign and malignant LNs. These improvements can potentially obviate the need for FNA in post thyroidectomy cancer patients.

Applications of 3-Dimensional Ultrasonography in the Neck, Excluding the Thyroid

Ultrasonography (US) of the neck is an accepted, useful imaging modality for many applications beyond its usefulness in thyroid disease. Two-dimensional US has been effectively used for evaluation of many types of neck conditions, and now, 3-dimensional US can be added to the imaging armamentaria. Three-dimensional US is useful in the evaluation of cervical lymph nodes, recurrent/residual thyroid neoplasia, parathyroid glands, parotid and submandibular glands, as well as thyroglossal duct cysts and other assorted palpable and visible abnormalities because of its unique capabilities, including multiplanar reconstruction, accessibility of the coronal view, volume calculation, and regularly spaced incremental slice evaluation.

Sensitivity of 3-Dimensional Sonography in Preoperative Evaluation of Parathyroid Glands in Patients With Primary Hyperparathyroidism

OBJECTIVES

Preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism facilitates targeted surgery. We assessed the sensitivity of 3-dimensional (3D) sonography for preoperative localization of abnormal parathyroid glands.

METHODS

We conducted a retrospective review of patients who underwent parathyroidectomy for primary hyperparathyroidism at a single site at our institution. We compared preoperative 2-dimensional (2D) sonography, 3D sonography, and sestamibi scans with final gland localization at surgery. Two readers reviewed the sonograms to assess inter-reader variability.

RESULTS

From January 2010 through April 2015, 52 patients underwent parathyroidectomy after preoperative 2D sonography, 3D sonography, and sestamibi scans. Three-dimensional sonography had sensitivity of 88-92% compared with 69-71% for 2D sonography for gland localization. In patients in whom sonography and sestamibi scans localized abnormalities to the same side, the sensitivities were 100% (43 of 43) for 3D sonography and 96% (48 of 50) for 2D sonography. Three-dimensional sonography had significantly higher sensitivity for localization of glands smaller than 500 mg compared with 2D sonography (88% versus 58%; P = .012). There was better inter-reader agreement between the radiologists when using 3D sonography (κ = 0.65) compared with 2D sonography (κ = 0.41).

CONCLUSIONS

We found a significantly higher sensitivity and better inter-reader agreement for 3D sonography compared with 2D sonography for preoperative identification of abnormal parathyroid glands, especially among smaller glands.