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

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.