The NeuroEXPLORER (NX) is a next-generation human brain PET/CT imager developed collaboratively by Yale University, the University of California, Davis, and United Imaging Healthcare. The NX features high spatial resolution, high sensitivity, and a built-in 3D camera for markerless continuous motion tracking. It offers a 52.4-cm transverse field of view (FOV) and an extended axial FOV of 49.5 cm, enhancing sensitivity. The system's performance was evaluated using the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard, demonstrating high spatial resolution (transverse: 1.64-2.51 mm, axial: 2.73-2.93 mm), time-of-flight (TOF) resolution of 236 ps, and energy resolution of 10.5%. The NX achieved a sensitivity of 46.0-47.6 kcps/MBq and a peak noise-equivalent count rate of 1.31 Mcps. Phantom studies and initial human imaging showed high-quality images with clear delineation of brain structures, including subcortical regions and small nuclei. The NX's capabilities extend to spinal cord imaging and image-derived input functions from the carotid arteries, broadening the range of applications in neuroimaging and clinical research.The NeuroEXPLORER (NX) is a next-generation human brain PET/CT imager developed collaboratively by Yale University, the University of California, Davis, and United Imaging Healthcare. The NX features high spatial resolution, high sensitivity, and a built-in 3D camera for markerless continuous motion tracking. It offers a 52.4-cm transverse field of view (FOV) and an extended axial FOV of 49.5 cm, enhancing sensitivity. The system's performance was evaluated using the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard, demonstrating high spatial resolution (transverse: 1.64-2.51 mm, axial: 2.73-2.93 mm), time-of-flight (TOF) resolution of 236 ps, and energy resolution of 10.5%. The NX achieved a sensitivity of 46.0-47.6 kcps/MBq and a peak noise-equivalent count rate of 1.31 Mcps. Phantom studies and initial human imaging showed high-quality images with clear delineation of brain structures, including subcortical regions and small nuclei. The NX's capabilities extend to spinal cord imaging and image-derived input functions from the carotid arteries, broadening the range of applications in neuroimaging and clinical research.