High-resolution pinhole-SPECT (PSPECT) is a new method for examining the thyroid gland.
Methods: The camera is tilted slightly so that it is as close to the thyroid as possible. Patients are injected with 185-260 MBq (5-7 mCi) of [99mTc]pertechnetate and examined for 20 min. The reconstruction algorithm is based on filtered back-projection.
Results: We performed static scintigraphy on the thyroids of 114 patients, followed by PSPECT. The major advantage of P SPECT is high resolution. Three- and 4-mm-pinholes produce resolutions of 6 mm and 7 mm, respectively, while resolutions obtained with a parallel collimator are always above 15 mm. The second advantage associated with this method is the good visualization of the cold nodules surrounded by higher activity. Finally, the reconstruction program provides exact sizes of thyroids.
Conclusion: SPECT is a powerful tool for examining the thyroid.