Three-Phase Parathyroid 4-Dimensional Computed Tomography Initial Experience

Abstract

Initial results after implementation of 4D-CT show high accuracy of interpretation for inexperienced observers, comparable to published data, and high interobserver agreement.

Organs’ absorbed dose and comparison of different methods for effective dose calculation in computed tomography of parathyroid glands

“…ED calculations were based on an approach including the use of a combination of two different k-factors and the corresponding scan lengths, at the anatomical areas scanned during each phase; neck (pre-contrast phase) and neck-chest (arterial phase). For the neck and chest region, k-factors within the ranges of 0.0051 to 0.0059 mSv mGy −1 cm −1 [22,[31][32][33] and 0.014 to 0.017 mSv mGy −1 cm −1 [31,39] have been suggested, respectively. However, in most previously published studies regarding CT of parathyroid glands, a single k-factor of 0.0054 mSv mGy −1 cm −1 has been used [22,31,32].…”

“…For the neck and chest region, k-factors within the ranges of 0.0051 to 0.0059 mSv mGy −1 cm −1 [22,[31][32][33] and 0.014 to 0.017 mSv mGy −1 cm −1 [31,39] have been suggested, respectively. However, in most previously published studies regarding CT of parathyroid glands, a single k-factor of 0.0054 mSv mGy −1 cm −1 has been used [22,31,32].…”

“…In the case of a three-phase protocol, if the same scan length is used in all phases [28][29][30][31][32][33][34][35][36][37][38], the patients' ED could be calculated by modifying equation (9) as follows:…”

“…Based on the fact that parathyroid adenomas enhance maximally in the arterial phase, several studies have suggested two-phase protocols to reduce the patient dose [19][20][21][22][23][24][25][26]. On the other hand, evidence exists to support the use of dynamic protocols (by adding one or two delayed phases) for the complete characterisation of parathyroid lesions in relation to their surrounding tissues (thyroid and lymph nodes) in challenging cases, such as multiglandular or recurrent disease [27][28][29][30][31][32][33][34][35][36][37][38][39][40]. In general, parathyroid glands CT consist of an unenhanced and one or more contrast-enhanced phases to enable the discrimination between parathyroid adenomas (PAs) and their neighboring mimics.…”

Prospective Validation of Two 4D-CT–Based Scoring Systems for Prediction of Multigland Disease in Primary Hyperparathyroidism

“…However, previous studies have shown high concordance in 4D-CT interpretations between neuroradiologists, suggesting that assignment of MGD scores is likely to be highly reproducible. 14,15 Last, a patient population presenting to a single institution may represent inherent bias. Thus, the applicability of the MGD predictive score system should also be prospectively validated in a multi-institution setting.…”