Abstract
Quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate aids in evaluating salivary gland function. However, gland segmentation and quantitation of gland uptake is challenging. We develop a salivary gland SPECT/CT with automated segmentation using a deep convolutional neural network (CNN). The protocol comprises SPECT/CT at 20 min, sialagogue stimulation, and SPECT at 40 min post-injection of Tc-99m pertechnetate (555 MBq). The 40-min SPECT was reconstructed using the 20-min CT after misregistration correction. Manual salivary gland segmentation for %injected dose (%ID) by human experts proved highly reproducible, but took 15 min per scan. An automatic salivary segmentation method was developed using a modified 3D U-Net for end-to-end learning from the human experts (n = 333). The automatic segmentation performed comparably with human experts in voxel-wise comparison (mean Dice similarity coefficient of 0.81 for parotid and 0.79 for submandibular, respectively) and gland %ID correlation (R2 = 0.93 parotid, R2 = 0.95 submandibular) with an operating time less than 1 min. The algorithm generated results that were comparable to the reference data. In conclusion, with the aid of a CNN, we developed a quantitative salivary gland SPECT/CT protocol feasible for clinical applications. The method saves analysis time and manual effort while reducing patients’ radiation exposure.
Highlights
Salivary glands are multifunctional organs with protective, digestive, exocrine, and endocrine functions
Traditional nuclear imaging of Tc-99m pertechnetate salivary scintigraphy has advantages and disadvantages[3, 5,6,7,8,9], but it is uncertain whether salivary gland scintigraphy has played a proper role in salivary gland function evaluation, mainly because of poor reproducibility and lack of o bjectivity[5, 31]
Other nonnuclear imaging studies such as ultrasonography, CT, or MRI are emerging as alternatives to scintigraphy for a variety of salivary gland d iseases[32,33,34,35]
Summary
Salivary glands are multifunctional organs with protective, digestive, exocrine, and endocrine functions. Recent technological development has allowed the application of quantitative nuclear imaging parameters, such as %injected dose (%ID) and standardized uptake value (SUV), to SPECT/CT imaging[13,14,15,16,17,18,19,20,21]. The performance of human experts who trained the automatic segmentation algorithm has not been presented in previous s tudies[23, 25,26,27]. This study develops a novel salivary gland SPECT/CT protocol (pre-stimulation SPECT/CT and post-stimulation SPECT), in which salivary gland function is represented by the absolute quantitation of Tc-99m pertechnetate uptake (i.e., %ID). The performance of human experts who trained the automatic algorithm is presented
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
