3-phase dual-energy CT scan as a feasible salvage imaging modality for the identification of non-localizing parathyroid adenomas: A prospective study

Abstract

ObjectivesAccurate pre-operative imaging of parathyroid adenomas (PAs) is essential for successful minimally invasive surgery; however, rates of non-localizing PAs can be as high as 18 %. Multiphasic dual-energy CT (DECT) has the potential to increase accuracy of PA detection by enabling creation of paired material maps and spectral tissue characterization. This study prospectively evaluated the utility of 3-phase DECT for PA identification in patients with failed localizatio n via standard imaging.MethodsPatients with primary hyperparathyroidism and non-localizing PAs underwent a 3 phase post-contrast DECT scan acquired at 25, 55, and 85 s. The scans were prospectively evaluated by two head and neck radiologists. Pre-operative localization was compared to intraoperative localization and final histopathology. A post-hoc DECT spectral density characterization was performed on pathologically-proven PAs.ResultsOut of 29 patients with primary hyperparathyroidism and non-localized PAs, DECT identified candidates in 26. Of the 23 patients who underwent parathyroidectomy, DECT provided precise anatomic localization in 20 patients (PPV = 87.0 %), one with multi-gland disease. The virtual unenhanced images were not found to be useful for diagnosis but successful diagnosis was made without an unenhanced phase regardless. Spectral analysis demonstrated a distinct spectral Hounsfield attenuation curve for PAs compared to lymph nodes on arterial phase images.Conclusion3-phase DECT without an unenhanced phase is a feasible salvage imaging modality for previously non-localizing parathyroid adenomas. Optimal interpretation is achieved based on a combination of perfusion characteristics and other morphologic features. Advanced spectral DECT analysis has the potential for further increasing accuracy of PA identification in the future.

Thyroid surgery in 103 children in a single institution from 2000-2014

“…The recurrence rate for thyroid cancer in children after thyroidectomy has varied widely in reported studies, ranging from 0 to 47%, 16 - 18 , 30 - 32 while it was 10% in this cohort. Only a few studies explored the predictors of recurrence.…”

Dual energy 4D-CT of parathyroid adenomas not clearly localized by sestamibi scintigraphy and ultrasonography – a retrospective study

“…Some previous studies reported that the virtual non-contrast (VNC) phase is not useful in DE examinations because the iodine content is subtracted from both PAs and the Thy, leaving both tissues in the same HU range [5,9,12] in contrast to real non-contrast examinations where the Thy has higher HU values due to its natural iodine content. This concurs with our own observations using VNC images (data not shown).…”

“…Thus, in contrast to Forghani and Mukherji [5], we found that dual-energy data from all three phases are valuable in terms of the quantitative information they provide for the differentiation of tissues. Our arterial phase was taken after 30 seconds; previous studies have used approximately 25 seconds [5,10,12]; furthermore, our venous phase was taken after 75 seconds (compared to 45 -55 seconds in other studies). Roskies et al [12] also reported the use of an additional 85 second delay.…”

“…Our arterial phase was taken after 30 seconds; previous studies have used approximately 25 seconds [5,10,12]; furthermore, our venous phase was taken after 75 seconds (compared to 45 -55 seconds in other studies). Roskies et al [12] also reported the use of an additional 85 second delay. This might explain why we observed significant differences between all three structures in the venous phase in images taken at 90 kV, 150 kV, and in the mixed images.…”

Performance of the American Thyroid Association Risk Classification in a Single Center Cohort of Pediatric Patients with Differentiated Thyroid Cancer: A Retrospective Study

“…This is partly due to the lack of randomized trials in pediatric DTC, and treatment has mainly been based on adult guidelines. However, DTC behaves differently in children in comparison to adults; the clinical presentation is more aggressive and there is a higher risk of persistent and recurrent disease after initial therapy [1, 4, 7]. Further, as the disease-specific mortality related to thyroid cancer is extremely low in children, the AJCC staging remains limited in terms of prognostic significance in this group [14].…”