Technetium-99m SPECT/US Hybrid Imaging Compared with Conventional Diagnostic Thyroid Imaging with Scintigraphy and Ultrasound

Abstract

Side-by-side evaluation of thyroid ultrasound (US) and ^99mTcO₄ scintigraphy can lead to uncertainties in the correct topographic assignment of thyroid nodules. The aim of this study was to evaluate ^99mTcO₄ single-photon emission computed tomography/ultrasound (SPECT/US) fusion imaging. Seventy-nine patients were prospectively investigated. If conventional diagnostics of the thyroid gland (B-mode-US, scintigraphy) produced unclear findings, SPECT was performed and transferred to a US device for real-time sensor-navigated 3-D fusion US investigation. The data sets were manually matched according to their contours. Finally, SPECT/US versus conventional diagnostics was rated using an ordinal 4-point scale (SPECT/US >> conventional diagnostics, SPECT/US > conventional diagnostics, SPECT/US = conventional diagnostics, SPECT/US < conventional diagnostics). SPECT/US was superior (>>, >) in 84% and equivalent (=) in 16% of the cases, respectively. No statistically significant differences were observed for uni-, bi- and multinodular goiters (p ≥ 0.3). In 67%, the respective problem that arose after conventional diagnostics was clarified by SPECT/US. SPECT/US was feasible and was helpful for the clarification of uncertain functionality assessments of thyroid nodules.

Keywords: Fusion imaging; Hybrid imaging; Single-photon emission computed tomography/ultrasound; Thyroid; Ultrasound.