ABSTRACT Point-of-care imaging is highly desired in otolaryngologic clinics for the diagnosis of ear, nose and throat (ENT) diseases including cancers. Due to limited image quality, current cone-beam CT (CBCT) products act not as a substitute but rather as a complement to diagnostic Multi-slice CT (MSCT) in maxillofacial and ENT imaging. The emerging multi-source x-ray source technology suggests new designs of CT systems that may have faster imaging speed, improved image quality, reduced radiation exposure, and compact geometries. Tetrahedron Beam Computed Tomography (TBCT) is a compact volumetric CT based on linear array multi- pixel x-ray sources which can produce diagnostic-quality volumetric images but in a much more compact geometry than CBCT. During Phase I study, we successfully developed a benchtop ENT-TBCT system using a multi-pixel thermionic emission x-ray (MPTEX) source developed in-house and a state-of-art commercial photon-counting detector (PCD), and demonstrated the superior image quality that TBCT can achieve. During the Phase II study, we will further refine the MPTEX source and develop a clinical prototype system. To achieve this goal, we propose to perform studies to achieve the following Specific Aims (SA): SA 1: To develop a rotatable sealed MPTEX source; SA 2: To develop a clinical ENT-TBCT prototype on a rotating gantry; and SA 3: To develop advanced image reconstruction algorithm and perform benchmark imaging studies. The outcome of this research will be a highly effective point-of-care diagnostic imaging modality for otolaryngologic clinics. Future commercialization of the ENT-TBCT system will improve the quality and efficacy by supporting prompt diagnosis and treatment of ENT cancers and other diseases.