Diagnostic accuracy of 4D-CT for parathyroid adenomas and hyperplasia

Abstract

Background and purpose: 4D-CT is a novel method of multiphase CT imaging. When used to localize parathyroid adenomas and hyperplasia, this technique may allow for more robust diagnostic accuracy than traditional sonography and nuclear scintigraphy techniques. The purpose of our study is to assess the accuracy of 4D-CT for localizing pathologically proved parathyroid adenomas and hyperplasia found during surgery.

Materials and methods: A total of 35 pathologically proved cases of parathyroid adenoma and hyperplasia were retrospectively reviewed between January 2009 and March 2011. Inclusion criteria were availability of final surgical pathology and performance of preoperative 4D-CT. No cases were excluded. Sensitivity, specificity, and accuracy of 4D-CT were ascertained including both the side and quadrant of the pathologically proved lesion.

Results: Of the 35 pathologically proved cases collected over the study period, 32 (sensitivity = 91%) patients were found positive for parathyroid disease using 4D-CT, including 3 cases of multigland disease. For lateralization of single-gland disease, 4D-CT demonstrated an accuracy of 93%. 4D-CT revealed a suboptimal 44% sensitivity, but 100% specificity, for multigland disease.

Conclusions: 4D-CT demonstrated a high diagnostic accuracy for single and multigland disease in our cohort. Importantly, 4D-CT accurately lateralized single-gland adenomas in >90% of cases, allowing the surgeon to employ a directed operative approach. 4D-CT also showed a very high specificity for the detection of multigland disease.

Fig 1.

Axial noncontrast (A), axial early phase postcontrast (B), and axial delayed phase postcontrast (C) images show a hypoattenuated hypodense nodule contiguous with the left posterior thyroid gland, which demonstrates avid early contrast enhancement and washout. Pathology revealed a 600-mg parathyroid adenoma.

Fig 2.

Coronal early phase postcontrast (A), axial early phase postcontrast (B), and axial delayed phase postcontrast (C) images showing an early enhancing 1.3-cm nodule in the right tracheoesophageal groove, with modest contrast washout representing a right inferior parathyroid gland in an orthotopic location. Pathology demonstrated a 3-g parathyroid adenoma.

Fig 3.

Axial (A) and coronal (B) postcontrast images showing an enhancing retrosternal ectopic parathyroid adenoma.