ABSTRACT
Different types of nuclear imaging systems have been used in the past, starting with pre-operative gantry-based SPECT systems and gamma cameras for 2D imaging of radioactive distributions. The main applications are concentrated on diagnostic imaging, since traditional SPECT systems and gamma cameras are bulky and heavy. With the development of compact gamma cameras with good resolution and high sensitivity, it is now possible to use them without a fixed imaging gantry. Mounting the camera onto a robot arm solves the weight issue, while also providing a highly repeatable and reliable acquisition platform. In this work we introduce a novel robotic setup performing scans with a mini gamma camera, along with the required calibration steps, and show the first SPECT reconstructions. The results are extremely promising, both in terms of image quality as well as reproducibility. In our experiments, the novel setup outperformed a commercial fhSPECT system, reaching accuracies comparable to state-of-the-art SPECT systems.
Subject(s)
Gamma Cameras , Image Enhancement/instrumentation , Image Enhancement/methods , Robotics/instrumentation , Robotics/methods , Surgery, Computer-Assisted/instrumentation , Tomography, Emission-Computed, Single-Photon/instrumentation , Algorithms , Equipment Design , Equipment Failure Analysis , Humans , Miniaturization , Reproducibility of Results , Sensitivity and Specificity , Surgery, Computer-Assisted/methods , Systems IntegrationABSTRACT
We present a novel approach for intra-operative localization of lymph nodes and metastases in the head and neck region using the radio-tracer [18F]FDG. By combining an optical tracking system with a high-energy gamma probe to detect 511keV annihilation gammas, we enable intra-operative PET to visualize activity distributions. Detection of these gammas is modeled ad-hoc analytically, taking into account several factors affecting the detection process. This allows us to iteratively reconstruct the radio-tracer distribution within a localized volume of interest. As a feasibility study we analyze clinical data of 7 patients with tumors in the head and neck region, and derive a realistic neck phantom configuration with [18F]FDG-filled lesions mimicking tumors and lymph nodes. We demonstrate the capabilities and limitations of our approach using that neck phantom. We also outline possible improvements to make our method clinically viable towards less invasive surgeries.
