NOVEL TETRAHEDRON BEAM CT FOR POINT-OF-CARE IMAGING IN EAR, NOSE AND THROAT IMAGING - 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.